In the preparation of acrylic water repellent (PPSBC), cationized stearyl methacrylate-2-diethylaminoethyl methacrylate copolymer (SDMAC) and quaternized 1-behenoylaminoethyl-2-docosyl imidazoline(BADIC) were selected as a basic resin and the improving agent such as softening effect and hydrostatic pressure of the water repellent. PPSBC was prepared by blending waxes and emulsifier for waxes with various ratio to SDMAC and BADIC. As the results of the measurement of water repellency, washable, tear strength and crease recovery to cotton fabrics treated with PPSBC only or addition of textile finishing resin, the pysical properties were increased. Sodium acetate was the most effective catalyst in the water repellency among the various kinds of catalyst, and the reasonable concentration of the catalyst was 1.0 wt%. PPSBC was confirmed as durable water repellent with the results of making little difference of water repellency as $pm$5 point after and before washing. The reaction mechanism between cotton fiber and PPSBC in the presence of catalyst was proposed. And also, the longitudinal view of the cotton fiber treated with water repellent was observed with scanning electron microscope.