Abstract: The construction principle of dam safety management imformationization is what as below: basing on the technology of modern communication and information treatment, combining experience of foreign countries in this aspect with the dam safety management in China, establish a dam safety management and technology communication platform for the hydropower plants in electricity system. This systemshould be of authority, integrality and well- timed. The whole systemcontains the main systemat Large Dam Safety Supervision Center, systems at management departments and subsystems at operation departments. The clients may inquire about related standards, regulations, dam safety and monitoring data. When clients are far away from dam sites, they may get monitoring data by internet or mobile phone. In this system, Internet, mobile communication net, automatic monitoring systemas well as the technology ofWeb Services, XML and Smart Client were applied. After 2- year operation, the system is of good performance, worthy popularization nationally.