Abstract: As we know,Perturbation Method gives an effective way to analyze nonlinear probl ems but it is still very difficuit to solve step by step the linear problems obtained from the nonlinear problems after perturbation.On the other hand,Weighted Residual Method(WRM) has been succeeded insolving linear problems,but it is also difficult to hande directly non linear algebric equations by WRM alone. In this paper, we integrate the advantage of both the perturbation and WRM for applying to solve large deflection bending problems of composite laminated thin plates.This approach consists in linearizing a nonlinear problem with perturbational method at first,then solving resulted linear one in unified form with the use of the combination of quintic B-spline function as the basis of try-function by use of Least Square and Collocation Method.