Abstract: The problem of power quality severely impact on system stability and economic operation.However,the obvious deficiencies exit in the traditional power quality monitoring.To the increasingly power quality system,a system based on DSP+ARM is given.Making use of DSP powerful data processing capacity and high-speed A/D converter,the system meets the power monitoring requirements of high real-time performance.And it constitutes an Ethernet-based network of power quality monitoring system the use of ARM as a PC.