Several representative dredging materials in China, including muddy soil, silt, silty sand, and find sand, are selected and tested, to analyze and discuss the relationship between conductivity and concentration of dredging soil-water mixture and its influencing factors, also the feasibility of dredging slurry concentration determination by conductivity testing method. The conductivity of selected slurries with different concentration is tested, as well as the impacts of temperature and salinity on slurry conductivity. The results show that there is evident correlation relationship between slurry conductivity and its salinity, volume concentration, temperature. Moreover,sediment particle size gradation also has certain impact on slurry conductivity. Thus, it is feasible to determine slurry concentration by measuring its conductivity, when the influencing factors, such as salinity and temperature, are compensated or treated.