Considering the fact that when the cell temperature and solar insolation change rapidly, traditional variable step size(VSS) perturbation and observation(P&O) methods exist the defects that their tracking speed is relatively slow, there is small power oscillation around MPP(Maximum Power Point) and even some of them exist the situation of tracking unsuccessfully. This paper proposes a MPPT(Maximum Power Point Tracing) technology based on adaptive area algorithm. The simulation model of PV system is established by MATLAB. The simulation results show that the proposed method can track the MPP fast and accurately, and ensure the steady state characteristics of PV systems even when the climate conditions change rapidly. It effectively overcomes the defects of traditional variable step size perturbation and observation methods.