This paper analyzes the active and reactive power circulating current model of the paralleling inverters in typical microgrid and presents an improved adaptive droop controller to improve the performance of parallel-connected inverters. With the proposed control strategy， large fluctuations of bus voltage and system frequency caused by load variation can be avoided. It uses an adaptive integral loop gain to improve the dynamic performance of parallel systems. It also reduces unreasonable reactive power flow between the inverters in a microgrid， therefore avoids unnecessary power losses and additional equipment capacity. Simulation and experimental results confirm the validity of the proposed control technique.