In　order　to　study　the　effect　of　freezing　and　thawing　process　on　FDR　(frequency　domain　reflectometry)＇s　measuring　volumetric　water　content　of　soil,　the　TDR-3　soil　moisture　sensor,　based　on　FDR,　was　used　to　measure　volumetric　water　content　of　soil　at　different　temperatures　ranged　between　-20-20°C,　controlled　by　the　temperature　box　in　laboratory.　The　results　show　that,　before　freezing　process　above　0°C,　during　thawing　process,　the　volumetric　water　content　of　soil　measured　by　FDR　increases　or　decreases　as　the　temperature　increases　or　decreases;　the　volumetric　water　content　of　soil,　measured　by　FDR,　decreases　as　temperature　decreases　during　freezing　process;　and　increases　as　temperature　increases　during　thawing　process.　At　the　same　temperature,　the　volumetric　water　content　of　soil　measured　during　freezing　process　is　higher　than　that　measured　during　thawing　process;　at　0°C,　the　difference　between　them　is　maximal,　which　is　significantly　affected　by　the　initial　volumetric　water　content　of　soil　and　temperature.　The　results　are　valuable　for　improving　the　reliability　of　measuring　the　volumetric　water　content　of　soil　by　applying　FDR　in　freezing　and　thawing　process.