With　the　development　of　construction　project　the　durability　of　concrete　is　becoming　more　and　more　prominent,　and　surface　coating　is　an　effective　measure　to　enhance　the　durability　of　concrete.　Water-based　silicone　acrylic　emulsion　coating　and　water-based　fluorocarbon　resin　coating　were　chose　as　prime　and　topcoat　respectively.　The　impact　of　the　coating＇s　thickness　and　viscosity　on　the　durability　of　concrete　and　the　relationship　between　the　viscosity　of　the　coating　and　its　penetration　depth　were　testified　by　chloride　ion　permeability-resistance　property　of　concrete.　The　results　show　that　thickness　is　proportional　to　the　protective　performance　of　the　coating,　and　the　penetration　depth　highly　depends　on　viscosity.　And　the　result　of　coating-4　viscosity　method　shows　that　samples　with　viscosity　between　15　and　25　seconds　have　better　chloride　permeability　resistance.