Firstly, the microfiber synthetic leather was pretreated with formic燼cid, and then the epoxy resin(1, 4 - butanediol two water loss glycerol ether )was as crosslinking agent, collagen was as modifier to improve the water vapor permeability of microfiber synthetic leather base. The results show that the optimum modification condition are that the collagen dosage is 14%(basing on the weight of dry base), the dosage of epoxy resin is 12%, the treat reaction time by epoxy resin is 3h,and the best treat time by collagen is 2h,the reaction temperature is 40℃.The water vapor permeability, and Hydroscopicity of microfiber synthetic leather base increase by 43.0%and 25.56%, respectively. The Fourier Infrared spectrum analysis (FT-IR) results indicate that the collagen is successfully grafted on the surface of the base throught epoxy resin. The comparison between unmodified and modified bases was carried out with Scanning Electron Microscope (SEM),The results show that the fiber is more loose after being modified. Compare the bases before and after being modified with Atomic Force Microscope (AFM), the results show that the surface of the modified base is smoother and flatter. Moreover, Contact angle analysis also shows that the contact angle of modified base decreases significantly compared with the unmodified bases.