Tracked　vehicles　assume　an　important　role　in　engineering　and　agriculture.　Supporting-trafficability　is　the　lifeline　of　tracked　vehicles.　The　terrain　characteristics　is　concerned　with　the　relationships　critical　in　defining　the　mobility　of　tracked　vehicles.　Conventional　terramechanics　models　cannot　accurately　describe　the　relationship　between　tracks　and　soil.　A　major　problem　is　that　these　models　do　not　account　for　the　water　content　in　the　soil　and　sinkage　speed.　Water　content　is　an　important　factor　affecting　sinkage　of　vehicles,　which　in　turn　affects　vehicles＇　driving　resistance.　Increased　driving　resistance　is　a　barrier　to　the　mobility　of　an　tracked　vehicle.　Considering　sinkage　speed　is　conducive　to　describe　the　trafficability　of　tracked　vehicle　moving　at　high　speed.　In　this　paper,　the　terrain　characteristics　to　describe　the　relationship　of　the　pressure/sinkage　of　four　common　soil　types　in　Southwest　China　were　measured　using　soil　bin　tests.　We　discuss　characteristics　like　high　sinkage　speed,　water　content　variation,　and　repeated　loading,　as　well　as　the　relationships　of　these　major　factors　with　the　deformation　of　soil.　We　present　a　method　to　deduce　the　pressure-sinkage　relationship　for　track　shoes　using　the　stress-displacement　relationship　model　proposed　by　Bekker.　The　described　method　advances　the　study　and　understanding　of　track-terrain　interaction　in　complex　environments.　(C)　2018　Published　by　Elsevier　Ltd　on　behalf　of　ISTVS.