This　paper　reviews　the　research　status　of　surface　pretreatment　and　the　effects　of　surface　state　on　joint　strength　in　dissimilar　materials　joining.　Some　conclusions　are　as　follows:　1)　Depositing　an　active　metal　can　form　well　solid　solubility　with　the　base　material　or　the　filler　metal　in　dissimilar　materials　joining,　which　can　enhance　the　interface　reaction　and　improve　the　joint　strength;　2)　The　activity　of　surface　elements　is　promoted　and　the　diffusion　ability　is　enlarged,　the　hard　brittle　phase　in　the　joint　is　reduced　and　the　joint　strength　is　improved　by　perfecting　the　physical,　chemical　or　mechanical　properties　of　the　base　material.　©,　2015,　Beijing　University　of　Technology.　All　right　reserved.