In order to improve the hydrophilic property of polymer films, coating solutions which showed a good hydrophilic property, were prepared by the sol-gel method. The coating solutions were prepared by adding different types of silane coupling agents (aminosilane, epoxysilane and acrylsilane) to a colloidal silica (15 nm diameter). The solutions prepared by adding aminosilane resulted in gels which could not be used as coating solutions. On the other hand, the coating solutions prepared by the addition of epoxysilane showed contact angles of 10~15° and good hydrophilic property at R=0.10~0.15 (R=silane coupling agent/colloidal silica weight ratio). In addition, the coating solutions prepared by the addition of acrylsilane at R=0.03~0.07, exhibited contact angles of 5~10°, which means better hydrophilic property than aminosilane or epoxysilane.