Abstract: During recoverying ethane from natural gas in cryogenic process, CO₂ in natural gas mixtures easily forms into frost and causes plugging problems due to the low temperature in top of the demethanizer and the cold box. Regularity for the freezing point temperature of CO₂ in CH₄-CO₂ binary system is studied and it can help engineers to optimize the cryogenic separation process and avoid CO₂ freezing, and then reduce consumption of cold energy. For this propose, the saturated vapor pressure correlation of pure component CO₂ is modified to predict the temperature of CO₂ freezing point in vapor phase. The calculation results using the literature correlation, HYSYS software, Aspen Plus software, and correlation raised in this paper are compared with the Agrawal experimental data. The results show that this correlation has higher accuracy which the average deviation is within 2 ℃. In addition, a correlation for CO₂ solid formation temperature in the CH₄-CO₂ binary liquid system is given. Compared with Kurata experimental data, the correlation has the highest accuracy which the average deviation is within 1 ℃, and has wide generality.