Maximum Power Point Tracking (MPPT) algorithms are employed in photovoltaic (PV) generation systems to make full utilization of PV array output power which varies with external environment and loads. Aimed at the low efficiency of constant voltage method and the difficultly in choosing the iterative step size of incremental conductance method, the constant voltage with incremental conductance MPPT method was presented, and the rapid response was acquired by constant voltage method for the drastic change in outside environment. On the basis of the constant voltage method, the incremental conductance method with optimized small iterative step size was proposed to eliminate the power oscillation around maximum power point (MPP), and the maximum power point of PV array was approximated, thus the system efficiency was improved. Simulations results show that the PV generation system has good steady state and transient characteristics with the proposed maximum power point tracking method.