Abstract: In this study, Homotopy Perturbation Method (HPM) is implemented to solve system of differential equations. The HPM deforms a difficult problem into a simple problem which can be easily solved. The results are compared with the results obtained by exact solutions and Adomian`s decomposition method. The results reveal that the HPM is very effective, convenient and quite accurate to systems of nonlinear equations. Some examples are presented to show the ability of the method for linear and non-linear systems of differential equations.