The poor adhesivity between diamond coating and cemented carbide substrate due to is the big difference in properties of diamond and cemented carbides, especially in the presence of Co in the substrate, which has the deleterious effect and brings about the transformation of diamond to amorphous and graphitic carbon. How to improve the adhesivity is very important for the products development of carbides with diamond film. The adhesivity can be improved by strictly controlling the process of diamond depostion, but the surface pretreatmetn of cemented carbide substrate is another more important approach to improve the adhesivity. The main factors effecting the adhesivity are briefly introduced, and the recent advances in the research of surface pretreatment of cemented carbide substrate for diamond coating are reviewed.