In　order　to　better　understand　the　improvement　mechanism　of　Fiber　Reinforced　Plastic　(FRP)　on　asphalt　mixture　performance,　this　research　investigated　the　adhesion　between　asphalt　and　FRP　by　using　surface　free　energy　method.　The　contact　angle　of　asphalt　was　measured　by　sessile　drop　method,　and　the　contact　angle　of　FRP　was　measured　by　monofilament　infiltration　method.　Results　show　that　the　polarity　of　the　asphalt　was　weaker　than　FRP.　The　surface　free　energy　of　asphalt　with　the　penetration　grade　90　was　bigger　than　penetration　grade　70.　Addition　of　mineral　fillers　made　the　surface　energy　significantly　reduced.　Under　the　dry　condition,　the　work　of　adhesion　between　rubber　asphalt　and　FRP　was　the　largest.　Under　the　damp　condition,　the　work　of　adhesion　of　all　asphalt—FRP　combinations　were　greatly　improved.　©　2018　Taylor　&　Francis　Group,　London.