Abstract: Corrosion of carbon dioxide means the corrosion made by carbonic acid generated after carbon dioxide (CO₂) dissolved in water. Summarizes corrosion mechanism of carbon steel under carbon dioxide environment, having and not having corrosion product scale on carbon steel's surface. And analyzes that temperature, CO₂ partial pressure, flow speed, pH value and corrosion product scale effect on CO₂ corrosion. It is thought that the corrosion mechanism of CO₂ to carbon steel will vary with FeCO₃ film formed on metal surface, CO₂ partial pressure and flow speed affect cathodic process of corrosion and temperature is the major condition effecting on the formation of corrosion product scale. Conducting basic and applicable study in partial corrosion field will be helpful for corrosion control of oil and nature gas.