Octadecyl Dimethylamine is an important organic synthesis intermediate of quaternary ammonium salt type cationic surfactant. It can react with ethylene oxide, dimethyl sulfate, diethyl sulfate, methyl chloride, benzyl chloride, etc. to form different quaternary ammonium salt, which can be used for fabric softening, antistatic agents, hair combing and other products. It can also be used to produce insect repellents. The reaction of N,N-dimethyloctadecylamine with ethylene oxide and nitric acid produces octadecyldimethylhydroxyethyl quaternary ammonium nitrate, an antistatic agent SN.