To navigate pathways for China's decarbonizing pledge, in this study, we investigated the energy consumption and CO2 emissions of China, and examined the potential of CO2 subsurface storage capacity with source-basin mapping. The results show that China's energy demand will keep increasing and reach 155,495 PJ in 2050. The annual CO2 emissions may peak at 9.8 Gt in 2025–2030 with about 377 Gt in total between 1990 and 2060. A national geological survey shows that 66.74% of geological basin spaces are onshore in China with 93.89% saline aquifers. Carbon capture and storage (CCS) for onshore basins can store 448 Gt CO2 in the most promising basin spaces (51 × 104km2) in China, which is sufficient to permanently store CO2 produced from 1990 to 2060 (377 Gt). A CO2 source-basin mapping suggests three scenarios based on the potential subsurface storage spaces, their locations from nearby CO2 emitters, and the economic feasibility. The CCS cost of China in equipment and material aspects is estimated 20% less than the US gulf coast, and the labor prices are the lowest in compared regions. Four phases are recommended for the CCS development, where the Ordos Basin is believed as the most potential region in all phases.