The Qiongdongnan Basin, located off Hainan Island, South China, is a petroliferous basin containing what is currently the largest offshore-producing gas fi eld in China (YA13-1). This paper evaluated the potential of CO 2 storage in the Qiongdongnan Basin to provide background data on CO 2 storage capacities for regional planning purposes. Four regional seals and high-quality reservoirs exists in the basin, in mostly marine sequences. The estimated mean effective CO 2 storage capacity of the basin is 41 Gt CO2 , determined from published data and the Carbon Sequestration Leadership Forum methodology for assessing oil and gas storage capacity; the majority of the storage capacity is in saline formations and oil and gas fi eld (15 Mt CO2 and 832 Mt CO2 , respectively). The prospective areas for CO 2 storage in the Qiongdongnan Basin are in the belts of the Northern Depression and the Central Uplift. The Yacheng Uplift, as the most favorable area for CO 2 storage, contains the YA13-1 gas fi eld, which has an estimated mean effective CO 2 storage capacity of 73 Mt CO2 . The Qiongdongnan Basin may provide storage sites for CO 2 stripped from the CO 2 -enriched gas from the basin itself, or from the emission sources in Hong Kong and Guangdong Province. However, industrial development on Hainan Island is weak, as the island was defi ned as an 'island for international tourism' by the Chinese govern- ment in 2009. The feasibility of transporting CO 2 to storage sites in the Qiongdongnan Basin using the pipeline now transporting gas from the YA13-1 gas fi eld to Hong Kong should be explored. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd