Energy is a critical issue in the network lifetime of a wireless sensor network (WSN). Thus, the main challenge in WSNs is to employ energy aware strategies. In this paper, our goal is to minimize total the energy consumption and to prolong the lifetime of a WSN by moving the base station (BS) to the best location in WSN. Therefore, a genetic based algorithm is proposed for finding the best location of BS in clustered-based WSN. Simulations have been conducted on the base of probabilistic and deterministic clustering strategies in WSN. Our simulation results compared with others algorithms and show that the proposed GA algorithm has a more advantage in increasing network lifetime.