In this paper, photovoltaic (PV) grid-connected inverter which is the core device in PV grid-connected system has been in depth research.An improved predictive current controller has been developed by the Authors for single-phase grid-connected voltage source inverters (VSI).Based on DSP TMS320LF2407A, a 10 kW single-phase grid-connected inverter has been built in this paper.Thus is aimed at use in distributed generation.Because of the powerful real time processing ability of the DSP, the output power factor of the PV inverter connected with grid can be controlled to unity. The composition of main circuit and control loop is described in detail and the operating principle of each functional block is analyzed deeply.The experiment results show that the improved predictive controller has a superior performance. The single-phase grid-connected VSI implemented with the proposed predictive controller has shown very low current THD in laboratory test Manuscript profile