In power system studies the most important issue is Transmission Expansion Planning (TEP). The intend of TEP problem is to choose the placement as well as number of additional transmission lines, which are to be added to the existing system to suit growing demand in planning horizon. In this paper a new methodology for TEP is proposed, the presented Transmission planning is linked with generation cost, active power loss minimization by considering wind uncertainties. Firstly, the uncertainties involved in wind generation can be determined by using weigbull probability functions. Monte Carlo simulation study is able to be used to find the probability distribution functions of wind generation. Then, in TEP formulation the WTG uncertainties are considered. Particle swarm optimization (PSO) technique is used for solving the proposed single objective optimization problem. Simulation studies conducted on an IEEE 30 bus test system to certify effectiveness of the TEP problem with considering wind uncertainties.