The rapid urbanization and changes in land use can result in imbalance between ecosystem services supply and demand at the regional scale, which is the major cause of regional ecosystem degradation. Therefore, it becomes essential to conduct quantitative analyses of ecosystem services supply and demand to identify key environmental issues and their driving forces in a region. In this paper, we present a comprehensive analysis of ecosystem services supply and demand dynamics during 1985-2015 for the Yangtze River Delta region, by employing the ecosystem services supply-demand assessment matrix approach based on land use and land cover types in the region. Our results showed 1) decreasing ecosystem services supply, but increasing ecosystem services demand for the Yangtze River Delta region over the past three decades. The area of the ecosystem service oversupply region decreased from 40.9% in 1985 to 38.5% in 2015, while the area of the ecosystem service undersupply region increased from 1.3% to 10.6% during the same period. 2) The ecosystem services supply-demand index value showed a "V" distribution pattern along the urban-rural gradient transects across Shanghai-Nanjing-Hangzhou. Peri-urban areas experienced dramatic decreases in ecosystem services supply-demand index value during the past three decades. 3) The area of the ecosystem services supply-demand surplus hotspot regions remained stable (only decreased by 0.1% over the past three decades), while the area of the ecosystem services supply-demand deficit hotspot regions increased dramatically by 14.9% during the same period. This indicates that the imbalance between ecosystem services supply and demand has become a critical issue for the rapidly urbanizing Yangtze River Delta region. 4) The ecosystem services supply-demand assessment matrix approach provides a simple and comprehensive way to quantify ecosystem services supply-demand dynamics of a region. The findings presented in this paper also provide new insights into regulating land use distributions and ecosystem conservation for rapidly urbanizing regions.