Abstract: In order to solve the problem of low accuracy and poor real time of traditional measuring instrument for soil EC, and according to the principle of measuring soil EC, NI Corporation graphical programming language LabVIEW and DAQ board were used to acquire soil temperature and soil EC, etc. A measuring instrument for soil EC was designed. Through simple operation, soil EC under different temperatures could be measured, and many functions were realized such as data display, data storage, data print and network transmitting. This instrument used temperature correction to eliminate measurement error of soil EC caused by the change of temperature. The results of testing EC of the KCl standard solution showed that the measuring instrument worked with a satisfactory accuracy, and it could be widely applied to measure soil EC. The research result provided a convenient methodology for validity measurement of many parameters.