The spatial-temporal differences of the level of service industry development (LSID), the level of influencing factors (LIFs) and their relationships in the Yangtze River Delta Region (YRDR) from 2006 to 2010 were assessed by principal component analysis and geographically weighted regression. These three aspects changed to different degrees and positions temporally. Spatially, the LSID presented significant urban hierarchy, and the LIF and their relationships showed obvious spatial disparities. Shanghai had not only the highest LSID but also the best comprehensive conditions for the service industry. However, the influencing intensity of such conditions lagged behind YRDR’s north- and south-wing cities.