Abstract: In this paper, the status of strong motion observation is introduced. The characteristic, function and developing trend of earthquake monitor in dam structure are illuminated. Some fuzzy understanding which exists in strong motion observation on dam in actual project application is pointed out. A new idea of strong motion observation with decision support system on the base of technique of computer and network, which of long-distance transmission and data base administration, is put forward. The system is studied and discussed on the technique outline of function, basic principle, general structure, and content of study and data flow. As an individual viewpoint, the direction of strong motion observation in hydroelectric project is brought forward, as well as the idea of realizing this viewpoint in technique.