Can I change employeer while my opt extension is pending ??? Any body has done this ????

I think yes. You just have to inform your school about the new employer. OPT is for you to work on your filed any where. You can change any employer, just make sure your school authorize that. They just look for the kind of work you are doing and should be somehwat related to your field.

thank you for your response.

yes I have talked to college regarding this. But If my opt extension is pending in uscis. We have to submit new i-20 of new employee from college to Uscis. College will update the  sevis online but we have send the old employer i-20 to uscis.
Any body have to face this stage ?????????????????????