In this paper, the photovoltaic inverter system with instantaneous sinusoidal current tracking control is proposed to improve the utilization factor of photovoltaic power system which would be connected utility interactive system. The proposed inverter is designed to track maximum power point by two-state value control method and utility interactive operation, and to decrease output harmonics component. Optimal operating region is described by state space averaging method, and present tracking condition of standard guide line. The experimental result shows the effectiveness of inverter system using the instantaneous control method.