The Japan consortium to enhance the CO2 sequestration into coal seams has carried out a project on CO2 injection at Yuhbari City, Hokkaido. However, supercritical condition of CO2 has not been satisfied due to heat loss along the deep injection tubing. The absolute pressure and CO2 temperature at the bottom hole are approximately 15.5MPa and 28ºC. Therefore, it can be assumed that CO2 is injected in liquid phase to the coal seam. The liquid CO2 causes decreasing injectivity into the coal seam due to high viscosity and swelling of the coal matrix. This study has provided a numerical procedure to predict the CO2 flow characteristics of pressure, temperature, supercritical or liquid in considering heat transfer from the injector to surrounding casings and strata. Present study has focused on the keeping supercritical CO2 in the tubing because viscosity of supercritical CO2 is 40% smaller than that of liquid CO2. The CO2 temperature has been successfully predicted in order to keep CO2 in supercritical condition from the surface to the bottom for various CO2 injection rates and electric heater power. Finally, Injected CO2 is expected to be supercritical over 12ton/day of injection rate without any heating.