This paper describes Transformer-less type utility interactive system that is combined with buck/boost chopper applying partial resonant method, which remove Transformer, and high efficient PWM inverter. Therefore, it is possible to make it lightweight, to cut down the cost, and to improve its reliability. What the merits of this system are that we can transmit arbitrary power arbitrary power to load and utility regardless of generating voltage magnitude of solar cell and we can always obtain high factor controlling by equal phase signal with utility.