This paper proposes a novel tracking algorithm considering radiation to improve the power of photovoltaic (PV) tracking system. Sensor method used in a conventional PV plant is unable to exactly track a sun position when intensity radiation is low, and has the problem that is malfunction of tracking system by a rapidly changing climate. Program method is generated power loss by unnecessary operation of tracking system because it is not adapted to weather conditions. This tracking system is not increased power more than the power of tracking system fixed a specific position due to these problems. To reduce the power loss, this paper proposes a novel control algorithm of the tracking system and proves validity of proposed control algorithm through compare with conventional PV tracking method.