Sodium 2-acrylamido-octyl sulfonate (NaAMC8S) was synthesized by using acrylonitrile and 1-octene as main raw materials. The optimum technology conditions are n(1-octene):n(acrylonitrile):n(fuming sulfuric acid)=1:6:1, reaction temperature 25 ℃, reaction time 24 h, the yield 82.2%(by 1-octene dollars). The structure of NaAMC8S was characterized with FTIR, 1HNMR, HRMS and EDS. The critical micelle concentrations at different temperatures were measured using methods of surface tension, conductivity and steady state fluorescence measurements, respectively. The experiment results show that the critical micelle concentration (cmc) of NaAMC8S is 44.75 mmol/L(by conductivity method) and 51.76 mmol/L(by surface tension method) at 25 ℃, and the according surface tension is 50.61 mN•m–1. Besides, the critical micelle concentrations of NaAMC8S do not change nearly with temperature.