Abstract: Synthesis conditions of 2-mercapto benzothiazole by reacting aniline with carbon disulfide and sulfur were optimized with single factor optimization and response surface methodology (RSM). Based on the results of single factor optimization，optimal stirring mode and catalysts were obtained，and the effects of such factors as temperature rise rate，heat holding time and substrate ratio were studied with RSM. A mathematic model of yield for 2-mercapto benzothiazole was established，and the best conditions were obtained：high temperature，high pressure and no stirring，salicylic acid as catalyst，and the mass of salicylic acid 5% of aniline，substrates mole ratio of aniline：sulfur：carbon disulfide = 1∶1.05∶1.11，temperature rise rate 1.93℃/min，reaction time 2.0h. The maximum yield was 92.08% under the optimal conditions，reaction time was shortened to 1.0h，temperature rise rate was reduced by 0.77℃/min，and the yield was improved by 6.2%.