This paper proposes a stochastic modeling of aggregated vehicle-to-grid (V2G) based on sequential Monte Carlo simulation for reliability evaluation of distribution network. Uncertainties of electric vehicle (EV) travel information including parking lot arrival time, travelled distance and parking lot departure time are incorporated into reliability evaluation using appropriate probability distribution functions. This model aids decision maker during planning phase to better estimate the impact of V2G on system reliability. The proposed model is used for optimal placement of a parking lot in an official center distribution network with the objective of reducing the expected energy not served.