The solvent based environmental friendly water-repellent reagent was prepared using epoxy and silicone resin as main filming material, low-toxic solvent as solvent, and nano-silica powders as filling. The water contact angle the paperboard coated with water-repellent reagent was up to 172. 4°. The optimum formula determined is epoxy resin (16% ), curing agent (7% ), silicone resin (6% ), silica powder (6% ), Dimethyl carbonate (60% ), and CBC (7% ).