In　the　paper,　Kevlar　fiber　was　modified　by　anionic　grafting　of　nylon　6.　The　mechanism　and　influence　of　transcrystallization　in　raw　Kevlar　fiber　reinforced　nylon　6.　composites　(PA6/KF0)and　modified　Kevlar　fiber　reinforced　nylon6　composites(PA6/KF1)　were　studied　by　PLM,　so　did　the　crystallization　instance.　The　results　show　that　both　KF0　and　KF1　can　do　crystalline　nucleation　to　matrix,　and　form　interfacial　transcrystallization;　At　certain　situation,　the　nucleation　of　KF　increases　with　temperature,　that　is　to　say,　higher　temperature　contributes　to　forming　compact　and　integrated　transcrystallization;　Because　the　modified　Kevlar　fiber　adjoins　the　matrix　well,　its　nucleation　is　stronger　than　that　of　the　raw　Kevlar　fiber.