A new system for automatic detect fault of water quality monitoring devices used in aquaculture is proposed in this paper. The proposed system can detect the whole system which includes platform gateway WSN sensor actuator. China is the world’s largest freshwater culture nation which provides 80% of the freshwater culture fish. The water quality is essential to freshwater culture, and the environment is controllable. In this paper, water quality sensors are used to detect the water quality of culture ponds. By the use of wireless sensor networks, the data can be sent to remote server. So farmers can check the state of the culture ponds where the internet is available. This paper is proposed to detect the state of the monitoring system, if the monitoring system falls, the system will alarm to the user.