Application of distributed generation particularly wind power plants in power systems, is rapidly increasing due to their various advantages. Considering the effects of these new resource impacts in power system planning, particularly TEP problem is inevitable, due to their essential role in changing the optimal plans. In this paper, a multi-objective optimization method is presented using DC load-flow in order to present a strong model for solving TEP problem. Considering uncertainties of wind farms generation and network load in the form of probabilistic variables, as well as the investment and maintenance costs in the objective function are the main advantages of the proposed algorithm. Multi-objective optimization problem has been analyzed using Imperialist Competitive Algorithm (ICA) which is one of the newest evolutionary optimization algorithms applied to power systems. To study the effects of wind farms on TEP problem and validate the proposed method, necessary changes have been made in RTS-IEEE 24-bus network and the presented algorithm has been applied to them. The results have been compared to optimum plans which were searched by GA Algorithm