Abstract: It is significant to design an electric conductivity gauge with the characteristics of high accuracy, easy operation and low price. As a part of TYZ-3 intelligent soil nutrition gauge, the conductivity gauge reached the aim mentioned above. The gauge is a kind of intelligent system designed on special software, which can compensate the measuring errors but on common electric parts. It has been shown that making measuring range into many different ranges for the operation to compensate the errors caused by distributed capacitance and temperature is not needed.