Just select the residue you'd like to highlight (either on the graphic interface - clicking on it or displaying the protein sequence on top of the main window- or by using the command line - select "surf-res", i. "insert residue number"-). Once you have the residue selected, just use the menu on the graphic interface to display it as stick.

Respected Almudena Pino Angeles,

thanks for ur comments on question. i think you dont understand what i am asking.. first i will represent the surface. Then with surface model i want that i have highlight some residues that will appear above the surface as shown in attached fig. The problem is that when i showed the surface and want to represent the residue above the surface, the residues are in the mid of the protein so they cant highlighted due to the upper surface model.

Hope you will understand my problem

After you have selected the residue and displayed it as a stick, you will have to hide the surface representation for that selected residue in order to show it over the surface of the protein.

What I don't understand is what you mean by the residue being in the mid of the protein: is that residue a surface one or is it buried? If the residue is not on the surface of the protein, but "on the inside", I am afraid you won't get anything similar to the example figure you've attached. In that case, you may want to play around with the transparency of the surface representation. By making the surface 40-50% transparent (maybe more, that will depend on your preference), you will be able to show a residue displayed as a solid stick in the inside of the protein. 

Maybe you could attach a picture of your structure, pointing out where the residue is? That way I'd get a better a idea of the specific problem.

Do you want to have a surface model and stick model? Can you represent your protein as surface, set transparency of surface to 50%, and then select the residues you want represent as stick and diplay/label.

Another (could be weird way but can surve your purpose) is to select your whole protein (except the residues of interest). Create the selection as an object1 and display it as surface. Then choose your residue of interest, create them as object2, and display them as sticks.

I created one for ubiquitin, while highlighting K27 according to your desired representation.

i have sent you fig.

when i hide the surface of the selected residues it creates whole in the surface of the protein as in fig.

thanks Ramesh,  yes that's like i want. How i can  Create the selection as an object1???

I would like to warn you that this kind of representation is quite misleading and uncommon.

But this is what you can do:

If I want to display residue 27 as stick and rest as surface in PDB 1UBQ here it is.

>sel resid 1-26+28-76

Go to Actions ("A") in the drop down menu on the right side of the PyMOL interface and click on "Create object"

This will give you obj01

>sel resid 27

and create obj02

Many many thanks Ramesh, its work.