Abstract: CO₂ corrosion environment of oil field was simulated in autoclave and corrosion behavior of 09Cr2AlMoRE steel was investigated.Average corrosion rate was calculated and composition of corrosion product was analyzed.It is found that uniform corrosion is dominate,the corrosion rate is quick and the composition of the corrosion scale varies at different test temperature but FeCO₃ is always the main ingrediant.The result indicates that the steel is not suitable for using in CO₂ corrosion environment and a proper consideration about working environment shall be taken when it is used.