The corrosion rate and characteristics of several kinds materials are studied under the in situ conditions of high pressure and high temperature in the stirring aqueous solution in a nickel-based alloy autoclave. The test results show that the corrosion rate and characteristics under different well conditions are different, the highest corrosion rate is 5 times greater than the lowest one. And in the same well, the corrosion rates of different materials and sections of a well are also different under the simulating test conditions. The differences come from the joint effects of multi-factors in different degrees. In different sections of a well, different corrosion characteristics of the same material are observed. As can be seen from the topography of the corrosion scales, the binding force of the corrosion scales with the base metal and the corrosion rate itself, the most serious corrosive section is at a depth from 1500m to 3500m, with the top 1500m part slightly corroded. At the bottom of the well, the corrosion is also gentle according to the formation of corrosion scales and the excellent binding force which would obstruct the corrosion process. Therefore, many factors should be considered when studying the CO₂ corrosion characteristics of tubing materials in deep or super deep wells, such as the tendency of the corrosion rate, and the conditions of the well. The temperature, the pressure and the flow rate of each well in different sections should also be tested and calculated to find out the most serious section under the corrosion, conditions and the effects of different factors are not the same on the corrosion rate. Therefore, the joint effects of all factors should be considered when studying the CO₂ corrosion of tubing.