Sunmide WH-900 is a low viscosity, high molecular weight, special amine adduct which is designed by new technology, dissolved in water. Reactions of Sunmide WH-900 with liquid epoxy resins are quick, have high crosslink actions, and will produce some network structures which can be used for anti corrosive applications. Low crosslink action solid epoxy resin react slowly with Sunmide WH-900, but quickly increase in their molecular weight with reactive process, and can be used for chemical resistant applications. This waterbased hardener has the ability to effectively cure and emulsify many epoxy resins in water. It has better curing properties than other waterbased hardeners at low temperature 10°C, high humidity 85%. Sunmide WH-900 formulations based on liquid epoxy resins are all solvent-free, and have good anti corrosive and adhesive properties which are especially suitable for use in concrete. Sunmide WH-900 formulations based on solid epoxy resins have good chemical resistance and long pot life properties.