Asphalt　pavement　is　inevitably　affected　by　the　rainfall　in　service　stage.　The　interaction　between　vehicle　and　rainfall　would　cause　the　hydrodynamic　pressure.　What＇s　more,　pavement　temperature　also　is　changing　with　time.　Temperature　history　and　hydrodynamic　pressure　would　influence　the　moisture　diffusion　in　the　pavement.　Thereby,　moisture　uptake　of　stone,　asphalt　mortar　and　mixture　at　different　temperatures　and　pressures　were　obtained　by　weighing.　A　pressured　device　was　developed　to　evaluate　impact　of　pressure　on　the　moisture　uptake.　Diffusion　coefficients　of　those　materials　were　determined　based　on　Fick＇s　second　law.　And　then,　2D　micro　mechanical　FE　model　of　asphalt　mixture　was　developed　with　the　help　of　digital　image　processing　technology.　Effects　of　temperature　and　pressure　on　moisture　diffusion　depth　were　analyzed　using　FEM.　Results　showed　that　the　rise　in　temperature　and　pressure　caused　the　increment　of　diffusion　coefficient.　This　also　resulted　in　the　ascending　of　moisture　diffusing　depth.　Influence　of　mortar　characteristic　on　moisture　diffusion　was　more　significant　than　that　of　aggregate.　Under　the　actions　of　wet-dry　cycles,　the　moisture　concentration　in　the　deep　part　of　mixture　risen　monotonously,　while　it　varied　periodically　in　the　shallow　part.　The　longer　the　drying　period　was,　the　lower　the　moisture　concentration.　Moisture　concentration　of　asphalt　pavement　may　be　largest　at　0.2-0.5　times　the　layer　thickness　after　intermittent　rainfalls.　Although　pressure　can　accelerate　the　diffusion,　influence　of　hydrodynamic　pressure　on　the　diffusing　depth　was　not　outstanding　since　the　actuation　duration　of　the　tire　on　pavement　was　too　short.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.