Hi.You can use self-concept questionnaire made by Susan  Harter

Hi Elaheh, thank you, it's helpfull

your wellcome

Harter's scales are good.  But may be less helpful for the preschoolers than for the older people's scale.  You need to be wary of "measurements" of these constructs before age 8-10.  Scores are not very stable from one measurement to another---not reliable.  The thinking is this is because recent experiences (like making a mess while painting the morning before testing in the afternoon) ) have a big influence on responses.   Preschoolers do not generalize or transfer from one situation to another.  Therefore, they don't have a "general self-.... summed across time, situations, activities.)   Harter's will give you a "Global Self- Worth sub scale, and that may be more helpful to you because it is based on feelings rather than skills, activities, etc. Also, beware that any self-concept measure is culture-bound. (To deal with that,  Harter's "Importance" sub-scales are really helpful.)

Thank you for your suggestions! Do you familiar with some other sub-scales for this age?  I need something more appropriate for non Western countries...   

Ah, you now confront  the "big problem" in self-esteem research... Self-value measurement often is based on asking about the degree to which one has traits valued within one's group/culture/society.  The traits that groups/cultures/societies value differ from culture to culture.  You need to know what is valued in a culture (often enacted in the behaviors that promote the society's goals for child-rearing)  before you can asses the traits.  That's is daunting to most and that is why many of the research studies compare the "valued traits" across cultures.   Go to Google Scholar and enter   You may find measurement scales in some of the scholarly article that you can use.  Best wishes.

Thank you