In this research, a genetic algorithm has been used to optimize the focal area of the parabolic trough concentration photovoltaic/thermal. First, based on the physical and thermodynamic variables, the system modeling was performed; then, by changing the variables were calculated the effect of these parameters on the electrical and thermal efficiencies. In the next step, the optimization was conducted by the mentioned algorithms. The objective function consists of two targets of electrical efficiency combined with thermal efficiency. The optimization variables include the length of the system, the pipe diameter, the collector diameter, mass flow rate, and the photovoltaic cell width. After running the program in the normal mode, the highest electrical and thermal efficiencies were 0.2063 and 0.4473 for the length of 10 m, the collector diameter of 1.2 m, the flow rate of 0.15 kg/s, the pipe diameter of 0.03 m, and the photovoltaic cell width of 0.02 m. According to the genetic algorithm, the optimal answer for the total efficiency of this system is 0.84737.