Gemini is a new kind of surfactant, compares with the conventional ones, its unique molecular structure entrusts with them better surface activity.In this dissertation, we made use of diethanolamine, long-chain bromo-alkane, 1'2 ethylene bromide as the raw materials, through two steps of chemical reactions, synthesized double(diethylols-alkyl) ethylene double quaternary ammonium salt surfacant Gemini An. The infrared spectrum was used to characterize the structure of Gemini An. We carried on the appraisal t...