It is very difficult for the conventional polymer flooding agent to meet the requirements of temperature resistance，salt tolerance and long-term aging thermal stability. The water-soluble hydrophobically associating polymer（PSA）was prepared by the copolymerization with acrylamide（AM）using N-phenethyl-N-dodecylmethacrylamide（PEDMAM）as associative monomer and 2- acrylamide- 2- methylpropanesulfonic acid（AMPS）as functional monomer. In addition，the comprehensive properties of PSA prepared at an optimum monomer（AM∶AMPS∶PEDMAM）mass ratio of 83∶15∶2 were investigated. The results showed that， compared with partially hydrolyzed polyacrylamide（HPAM），PSA had good tackifying capacity，temperature resistance，salt tolerance，shear resistance，aging stability and oil displacement performance. Under the condition of 85 ℃ and 32 g/L salinity with 800 mg/L the mass concentration of Ca2+ and Mg2+，the viscosity of 1500 mg/L PSA solution was 16.3 mPa· s，and the retention rate of viscosity was more than 80% after anaerobic oxygen aging for 60 days at 85 ℃ . Moreover，the results of laboratory core displacement experiment showed that 0.7 PV 1500 mg/L PSA could further enhance the oil recovery by 35.05% over water injection，which was greater than that of 3000 mg/L HPAM with similar viscosity by 12.35 percentage points. PSA had significant advantage in oil displacement.