s:The development of new energy vehicles (NEVs) is one of the important paths for China to achieve its ”dual-carbon” goal. How to study CO 2 emissions reduction and potential of NEVs quantitatively in different times and regions is one of current research hot-spots. Based on all life cycle assessment (LCA), from fuel production, energy consumption, and different times and regions, this paper assesses quantitatively CO 2 emissions of ICEV, BEV, PHEV, FCEV in all LCA and the utilization stage, and analyzes CO 2 emissions reduction potential of FCEV at different times and region comparatively. The results shows that CO 2 emissions of ICEV ( 247,358.9kg) in LCA is the highest, and BEV’s is 22.9% of ICEV’s, FCEV’s is 48.1% of ICEV’s. CO 2 emissions from the utilization stage is highest in four stage: for ICEV is highest (92.5%) and for BEV is minimum (54.9%). As consumption of vehicle and CO 2 emissions of energy production, CO 2 emissions from the utilization stage in 2025, 2035 and 2050 is analyzed. For ICEV, CO 2 emissions in 2050 reduced about 30% compared to that in 2025. However for BEV and FCEV, it reduced about 50%. Finally, this paper choose three different regions (Inner Mongolia, Shanghai and Yunnan) because of energy characteristics for hydrogen production in 2025, 2035 and 2050, and predict CO 2 emissions reduction potential of FCEV. In Shanghai 2050, there would be 200,000 FCEVs and in the utilization stage, CO 2 emissions reduction potential is 6.568*10 9kg. This research is better to promote the low-carbon process for NEVs, and realizes ”dual-carbon” goal faster and provide reference for policy-making.