Benzotriazole is mainly used as rust-preventer, antifreezing liquid, antioxidant additive(including lubricating oil, hydraulic oil, brake oil, transformer's oil), emugent, water stabilizer, the additive for high molecular materials (polyester and polyesteramide) capacity of ultraviolet resistance and anti- static electricity, photographic antifogging agent, copper mine flotation, metal's slow corrosion etc