This study analyses how carbon footprints of electric vehicles (EVs) in China vary across regions and how they may evolve with power decarbonisation. It is understood that carbon footprints of battery electric vehicles (BEVs) depend largely on electricity mixes, but few studies have quantified their interregional divergence and future changes in China. Using THEMIS model as an integrated LCA framework, together with future electricity mixes from MESEIC, a cost optimisation model for the power sector, we calculate current and future carbon footprints of passenger vehicles in China. Results show that, carbon footprints of BEVs across all the 6 regions will drop from 265-419 gCO2e/km in 2017 to 116-383 gCO2e/km in 2050, or 141-266 gCO2e/km, with stringent carbon constraints applied to the power sector. The interregional divergence of BEV carbon footprints will shrink by 20% in the latter scenario. Under carbon constraints, BEV carbon footprints in East, Central, Northwest, and South will have their best-case reduction potentials, by 55%, 55%, 46%, and 5% respectively. Stringent carbon constraints lead to increased share of coal-based generation in North and Northeast, whose most favourable reduction potentials will be 42%, and 69%, respectively, when no carbon constraints exist.