Abstract: The automatic monitoring system for safety of earth-rockfill dams based on Internet of Things is established. Both the hardware and the software for nodes of sensors, routers and coordinator node are designed by using the wireless sensor network chip CC2530 and GPRS module. The wireless sensor network and geographic information system are integrated. The all-weather real-time monitoring, control and data acquisition of a series of parameters including dam deformation, seepage, stress and strain as well as environmental and meteorological observations are achieved. Therefore the intelligent and scientific management of safety of earth-rockfill dams is realized with the help of the expert knowledge base.