In order to effectively achieve the data of the power quality management, analysis comprehensively, network sharing and classification, a power quality monitoring system based on Web is designed and developed in this paper. This design combines communication technology and database technology, using the B/S (Browser/Server) model which isa layered distributed structure. Through this system, users can real-time monitor the index of power quality and realize the network sharing of power quality date. The basic features such as high monitoring precision, easy upgrade and maintenance and flexibility were its advantages.