In my point of view, the term "political theory" implies a well-developed, more complex, position. Every one may have a political thought, but just a few are capable of developing a whole theory.

In David D. Raphael’s opinion (Problems of Political Philosophy, Macmillan, London 1990, pp. 5-21) political theory deals with political “facts”. It is allegedly scientific because value-free and descriptive. Thus it is different from political philosophy, which is normative in character. Political theory aims at describing few laws governing political life. Political philosophy aims at “critical evaluation of beliefs” – arguing in favor or against some beliefs – and “clarification of concepts”, to make the critical evaluation of beliefs even possible.

Similar definition of political theory (also focusing on political facts) is given by Leo Strauss, who defines it as a “comprehensive reflection on the political situation which lead up to the suggestion of a broad policy”. It is thus different from political thought understood as “reflection on, or the exposition of, political ideas; and by a political idea we may understand any politically significant ‘phantasm, notion, species, or whatever it is about which the mind can be employed in thinking’ concerning the political fundamentals. Hence all political philosophy is political thought but not all political thought is political philosophy” (Strauss, What is Political Philosophy?).

Often political theory is seen as a sub-field of political science.  Unlike other sub-fields of political science, political theory does not model its approach to knowledge on the natural sciences.  Political theorists see their field as among the humanities and as drawing from other humanities, such as the disciplines of ethics, history, linguistics, cultural anthropology, and other relevant fields.

Political philosophy is often seen as a branch of academic philosophy, with especially close and sometimes overlapping relationships to normative moral philosophy and meta-ethics.  Aristotle is particularly clear in underscoring his view of the reflexive nature of these relationships.

In comparing political philosophy with political theory, the scope and the broader more all-encompassing nature of political philosophy strikes me as essential.  Plato (Republic), Hobbes (Leviathan), and Marx (in the entire body of his work), are but three examples of political philosophers.  On the other hand, I would identify Machiavelli, James Madison, and Isaiah Berlin as three on many examples of political theorists.

A work of political philosophy is an attempt to achieve a level of generality which explores and draws conclusions about the nature and relationships between all the major features of government and politics, as well as the context in which political systems operate and are understood.  Works of political philosophy are grounded on significant assumptions about meta-physics and epistemology. Such works are also grounded theoretically by the mutually supportive nature of political principles, concepts, and institutions with fundamental moral principles, concepts, and institutions, such as justice, authority, human nature, and legitimacy. (This feature of political philosophy is no less the case in Marx's work than,for example, in the work of Plato.) The broad scope of political philosophy is complemented by its goal of presenting and defending timeless truths or bedrock meaning. (This is also the case with political philosophers, such as Hegel, for whom history, its laws of development and historical revelation and change are of central importance 

Of course, political theorists take an abstract approach, and  they investigate "the political" at a level of generality unfamiliar to scholars pursuing other sub-fields of political science.  Political theory has a focus on somewhat more specific basic or fundamental issues in politics than political philosophy.  There is far more attention to the development of mid-level or mid-range theory in approaching such issues than to ground understanding and to defend conclusions about politics in the most basic philosophical sub-fields,such as meta-physics, epistemology, or more recently linguistics and the meaning of meaning.

Machiavelli's concern with the principles and moral dilemmas of political leadership and the preservation and stability of a state led to conclusions in The Prince which are examples of mid-range theory that continue to stimulate examination and debate.  Madison's constitutional architecture was prompted by his deeply rooted goal to find institutional solutions under which citizens could be governed peacefully and effectively while, at the same time, prevent these political elites from becoming tyrants.  Madison's mid-range theory in achieving this goal is considered by many to be the most original and influential feature of the US Constitution of 1787.  Finally, Berlin's profound grasp of history and human nature were the tools he found essential to convincingly envision the possibility of tolerant and humane societies in which core objective moral values could be recognized and serve to guide action, while at the same time never forgetting that moral conflict between individuals, between individual societies, and even value conflict within the mind of each individual is inevitable and unavoidable.

Political thought refers to currents of how we may think, engage, generate what count as polities and their constituents.  Thought is of the milieu, as Isabelle Stengers would put it, much in line with Whitehead.  Theory seeks propositions that place parameters upon variant currents of  political life and thought, so as to advance a normative set of explanations of how political life will or may unfold.  Theory is of the programmatic, what is selected and organized as vital, and so is second order to thought.  The propositions developed of course can have more or less constitutive, agentive power to alter or stay the currents of political thought. 

In Anglo-American thought, the relationship between political theory and its mother discipline political science has been complex, dynamic, and contentious at times. For an excellent, but brief discussion of this relationship, please see The Blackwell Encyclopedia of Political Thought, edited by Miler, Coleman, Connolly, and Ryan. (1986) under "political theory and political science".

Many of the previous answers made reference to D.D. Raphael's conception of political theory found in Problems of Political Philosophy (1970).  This conception was presented in a period in political science when positivism and the research approach of behaviorism was dominant across the discipline. Raphael's definition of political theory as "scientific" and concerned with "facts" reflects the tremendous influence of behaviorism and the scientific model had on political science and all of its sub-fields.  

Even in the 1970's there were many scholars who rejected Raphael's definition, but certainly today political theory is generally regarded as a multidisciplinary activity which eschews value neutrality as well as the fact/value distinction. Political theory is a normative activity which approaches issues, such as justice, authority, liberty, democracy, equality, etc., by developing and defending value judgments through reasoned argumentation.  It is an illusion to expect political theory to generate principles with the degree of certainty that the natural science generates the laws of physics, for example.  This and other differences between political theory and the natural sciences make political theory no less important to a more complete and humane understanding of politics.

My own use of the two terms is based on my encounter with the so called Cambridge history of political thought (including Pocok, SKinner, John Dunn, Richard Tuck, and of course Istán Hont, too). I regard political thought as the one which is rooted in actual political practice, and which reconnects into it, while political theory is an academic enterprise, not directly connected to actual political practice.

A third level migh be distinguished, too: political philosophy, which is a subdiscipline of philosophy, related to matters political.

Ferenc Horcher's comment and my own above are in agreement.   And yes it is important to add in political philosophy, as it often seeks to do a more robust job of dealing with and bringing together both political theory and political thought.   For a dynamic example of this, see James Tully's Public Philosophy in a New Key.   Tully is a colleague (and former student) of Quentin Skinner.

In a very short answer: Political theory is the combination of different political thoughts on a subject related to politics. In other words, political thoughts come from different thinkers and then they combine a theory(if accepted by the authorities from the field)

Of all the questions that can be posed about politics, some are empirical (addressed by political scientists generally) and some are philosophical (addressed by political philosophers, without regard to academic department). Some sorts of political theory are empirical theories (theories of how democracies work, theories of IR) while others border on political philosophy; near this border, the terms become synonymous. Typically, because philosophical questions about politics are born of philosophical questions about what it means to be human and what is our place within the universe, political philosophers address (or assume) background theories of the nature of reality (aka metaphysics), accounts of human nature, and accounts of human morality; from these, political philosophies emerge. In this way, Berlin and Machiavelli are every bit as much political philosophers as are Plato and Aristotle.

There is no obviously similar way to account for the relationship of these to political thought, although "history of" tends to precede "political thought" more frequently than the other two.

Of all the questions that can be posed about politics, some are empirical (addressed by political scientists generally) and some are philosophical (addressed by political philosophers, without regard to academic department). Some sorts of political theory are empirical theories (theories of how democracies work, theories of IR) while others border on political philosophy; near this border, the terms become synonymous. Typically, because philosophical questions about politics are born of philosophical questions about what it means to be human and what is our place within the universe, political philosophers address (or assume) background theories of the nature of reality (aka metaphysics), accounts of human nature, and accounts of human morality; from these, political philosophies emerge. In this way, Berlin and Machiavelli are every bit as much political philosophers as are Plato and Aristotle.

There is no obviously similar way to account for the relationship of these to political thought, although "history of" tends to precede "political thought" more frequently than the other two.

Thanks for your answers of my question . my conclusions about the differences between political thought and political theories not only  of these empirical or philosophical  but on its type of thinking method . Every political thought have in it political theory , and not only every political theory have in it political thought .