Abstract: This paper has studied the regular pattern of oxidization corrosion of T225NG and T42NG anium alloy under high-temperature and high-pressure with long time. The element of the oxide film on surface, constitution and microstructures have been tested and analyzed, and the model of corrosion dynamical for T225NG and T42NG alloys has been tested and analyzed. The same time, the corrosion mechanism has been analyzed briefly .The results indicate that the main element Ti oxides first, and element Al and the impurity elements such as Fe, N, H, C promote corrosion behavior. All of this shows typical crystallographic character. The corrosion dynamics pattern of these two alloys all submits Para-curve in Wagner theory.