ABSTRACT For their superior CO2 corrosion resistance and relatively low cost the new generation of low Cr (3 to5%) bearing steels seem to be a good choice to meet the demand of preventing wet CO2 corrosion of sub-sea wet gas pipelines. The data of extensive laboratory assessment and field experience have confirmed that low Cr bearing steels have an improved corrosion performance when immersed in CO2 containing solutionswhile the resistance to wet CO2 corrosion has not been clarified. In this paper the effect of temperature on wet CO2 corrosion of 3%Cr pipeline steel was investigated. Wet CO2 environment in sub-sea wet gas pipelines was simulated in a high temperature and high pressure autoclave. A series of experiments were carried out at gas temperature 30-90°C while the cooling temperature was kept relatively low to provoke water condensation on the surface of coupons ranging from 10°C to 20°C. To make a further understanding of the effect the temperature of the liquid film and the condensation rate were predicted. The corrosion rate was determined by weight loss measurement. Scanning Electron Microscope (SEM) and Energy Dispersive Spectrum (EDS) were employed to analyze the corrosion scales. Keywords: Wet gas low Cr bearing steels CO2 corrosion temperature