The paper describes a successful adaptation of the Genetic algorithm based on similarity for solving power flow (OPF) problem in power systems. In the proposed method, three different similarity measurements have been used for calculating new chromosomes. The proposed approach which is evaluated on standard IEEE 30 bus system is implemented to minimize the total fuel cost considering power flow equations and generation, transformer and security constraints. The feasibility of the proposed method is compared to other methods in the literature. The simulation results show that the proposed approach is efficient and suitable and seems to be a promising alternative approach for solving the OPF problem in power systems.