Long time corrosion is carried out on a kind of new Ni-based super alloy used as a component of gas turbine engine, under salt-fog atmosphere at 700°C850°C for 200h. The salt solution component is 75% sodium sulfate plus 25% sodium chloride. The surface of the alloy was coated with salt solution at 150°C and aged at 700°C,750°C,800°C and 850°C for 10h, 50h, 100h and 200h, respectively. It is found that with the increase of temperature and aging time, the weight and thickness of the corrosion layer increase, and the corrosion becomes severer on the alloy surfaces. In the beginning of high-temperature corrosion, the corrosion speed increases quickly, and as prolong of corrosion aging time, corrosion speed turns to be invariable, and it is correlated to the formation of an oxidized layer by which the increasing of corrosion speed is restricted.