Objective measurement of the supply-demand of ecosystem services and sustainable ecosystem management has received increasing attention from the scientific community and the general public. This study explored changes in the supply-demand of ecosystem services and their natural and social driving mechanisms using spatial analysis methodologies as well as the relationship between the supply-demand of ecosystem services and environmental justice in coastal regions in China. In this study, the ecosystem service supply-demand index (ESSDI) was proposed based on the ecosystem services provision index and the land development index. Results indicated that although the imbalance in the supply-demand pattern of ecosystem services was serious, the spatial imbalance in the supply-demand pattern of ecosystem services improved from 2000 to 2015. Notwithstanding that the correlation coefficient between natural factors and ESSDI was higher, the development of the economy and the improvement of the quality of the population also had a substantial effect on ESSDI and the improvement of environmental quality. The spatial imbalance in ESSDI also caused serious environmental injustice as a result of differences in natural background, national policies, development gaps, trade, and industrial shifts. However, the implementation of some ecological compensation projects changed the spatial imbalance in ESSDI and relieved the environmental injustice. This research supports auxiliary decision-making for the sustainable management of regional ecosystems.