CO₂ geological sequestration is one of the most promising methods for reducing anthropogenic CO₂ emissions into the atmosphere. Therefore an assessment should be performed to determine whether there is sufficient CO₂ storage capacity in a country, a region or a specific storage unit. Current study results indicate that CO₂ storage estimation is not a simple and direct process. This paper introduced the method of CO₂storage capacity estimation in oil and gas reservoirs, deep saline aquifers, and coal seams presented by the CSFL Task Force. The main factors which may affect the estimation of CO₂ geological storage capacity were presented, and some suggestions about the national collaborative program on the research of CO₂ geological sequestration technology in China were put forward, which will be useful to the reduction of CO₂ emissions in China.