Unsaturated polyester resin is a condensation polymer formed by the reaction of polyols and saturated/unsaturated dibasic acids at 190-220℃ until the expected acid value or viscosity is met. After reaction procedure, addition of certain amount of styrene monomer to formed a unsaturated polyester resin. It possesses good mechanical and electric properties, corrosion resistance. Curing can occur at room temperaturewithout any heating equipment, and makes it easier to manufacture large objects.