Abstarct: In power systems, although the inertia energy in power sources can partly cover power unbalances caused by load disturbance or renewable energy fluctuation, it is still hard to maintain the frequency deviation within acceptable ranges. Especially in microgrids, that it's most power sources is renewable energy baxse. Nowadays, with the vehicle-to-grid (V2G) technique, electric vehicles (EVs) can act as mobile energy storage units, which could be a solution for load frequency control (LFC) in a microgrids. In this work, a new LFC model of micro-grid with EVs, Microturbine (MT) and fuel cell (FC) is proposed, where EVs and other sources are coordinated to achieve a satisfied performance on LFC. In the studied microgrid, the MT is normally used to provide the main power to the loads. Also, the large numbers of EVs are utilized in the consumer side. In this method, microgrid frequency adjusting by controlling the output power of microturbines, fuel cells and electric vehicles. It is baxsed on proportional-integral controller, but to determine the participation factor of microturbines, fuel cells and electric vehicles in frequency control, a new method is proposed. The proposed method is baxsed on the rated capacity and power product before changing the frequency for any unit. In addition, to optimize the controller parameters for microturbines, fuel cells and electric vehicles, particle swarm optimization (PSO) algorithm is used that improves the accuracy of frequency control. The effectiveness of the proposed algorithm is proved using simulation of a microgrid in Matlab software. Also, the impact of the presence or absence of fuel cell and electric vehicles in frequency control is investigated.The simulation results show that the proposed controller provides an excellent dynamic response with acceptable frequency deviation.