CONTRIBUTION Our work is the first to decompose the increase in Chinese national life expectancy into its regional contributing components of changing mortality and population exposure. This disaggregation of the different components at the regional level provides insights as to how to better address regional health inequality issues in China.BACKGROUND Life expectancy in China has been increasing in recent decades, but regional inequalities persist. Unbalanced regional development has resulted in large-scale population movement. Over time, the changing regional distribution of the population changes the proportion of the population exposed to different regional mortality levels. OBJECTIVE The increase in national life expectancy can be attributed to changes in both regional mortality and the regional composition of the population. We aim to quantify the respective contributions of changes in mortality and in the composition of the population. METHODS We apply a decomposition method to data from the Chinese Disease Surveillance Points system from 2010 to 2020 and disaggregate the improvement in Chinese life expectancy into mortality and composition components. RESULTS Improvements in mortality were observed across all regions, positively contributing to the increase in national life expectancy. However, only the most and least economically developed regions – urban-east, urban-central, and rural-west – made positive contributions through the compositional component. All other regions contributed negatively, partially offsetting the progress made by the improvement in regional mortality.