The relationship between sediment concentration in water current and output of capacitance sensor, and effects of temperature, flow velocity, soil types and its salinity content on the response of capacitance sensor have been studied for the first time by adopting two capacitance sensors different in structure.The results showed that the sediment concentration in water current is in linear correlation with the output of capacitance sensor, and the output of capacitance sensor increases with the temperature, but the effects of flow velocity, soil types and its salinity content on output of capacitance sensor were rather less.