Time domain reflectometry(TDR) is widely used in determining water content for general agricultural soils.But for soils with high bulk electrical conductivity,such as saline soils or heavy clay soils,the TDR measurement was not ideal because of dielectric losses.Based on experiments,this work intended to explain the phenomenon of TDR measured value deviating from actual water content.The result showed:when the water content was low(sand,<0.15cm³cm^-3;sandy loam,<0.18 cm³cm^-3),increasing electrical conductivity was not linely to induce a higher measured value.While the water content was high and the electrical conductivity up to 8 dS m^-1(sandy loam) and 11 dS m^-1(sand),TDR measured value was apparently higher than the actual water content.In the case of higher electrical conduct ivity(<16 dS m^-1),K a was still in linear correlationship with the actual water content,while the slope and int ercept were influenced by dielectric loss.In this study,a calibration equation was set up,considering the influence of electrical conductivity was set up.The increase in soil clay particle content also induced TDR measurement deviation.When the soil water content was low,the measured value was lower,and when the soil water content was high,the measured value was higher.If the clay content was<50%,the measured error would be<0.02cm³cm^-3.