Microgrid is a collection of electric loads, distributed generation units and battery storage operating as a controllable load which is able to supply the local loads. Air pollutions due to fossil fueled vehicles increase by factories development. Besides, shortage in fossil fuels increase the trends into electric vehicles. In this paper, optimal stochastic operation problem of microgrid in presence of electric vehicles and demand response loads is solved with the objectives of operation cost minimization and improving the security indices of the system in an acceptable level of the reliability. Besides, the optimal placement of PEV stations is performed. The proposed problem is formulated as mixed integer linear programming (MILP). Gams software is used as the simulation tool, and a 24-bus test system including a number of DGs, and PEV stations is studied to validate the efficiency of the proposed model