Silica sol/polyacrylate composite emulsion was prepared via emulsion polymerization with the product of hydrolyzed and condensed tetraethoxysilane(TEOS) instead of the commercial silica sol.The influences of pH value for TEOS hydrolysis, emulsion polymerization temperature and TEOS content(by mass) on the properties of composite emulsion were studied, and the Fourier transform infrared spectroscopy(FTIR) and transmission electron microscopy(TEM) were used to characterize the composite emulsion. The results show that the optimum pH value range for TEOS hydrolysis is 5.7~6.5, and the optimum emulsion polymerizaiton temperature is 75℃. With the increment of TEOS content, the stability of composite emulsion and the hardness of the film increase. However, composite emulsion will deposit and the film will crack with excessive TEOS. Experiments show that the optimum content of TEOS is 9%13%. In the preparation process, TEOS hydrolyzes and condensed to form complex of silica sol and polyacrylate. TEOS is used as silica sol and stabilizer, and the polymerization is carried out without additional stabilizer.