It is of great significance to clarify the evolution trend of hinterland of ports and to analyze the coupling coordination degree between ports and the hinterland in the Yangtze River Delta. The comprehensive index evaluation system for port system-hinterland system is quantified. For the three time nodes of 2006, 2011 and 2016, the influence intensities of major ports in the Yangtze River Delta are calculated using the Gauss plume model, and the hinterland area is divided. The coupling degree between the port system and the direct hinterland economic system is quantitatively analyzed by means of the coupling coordination model. The results show that the ports in the Yangtze River Delta exhibit a pattern of “one super-strong and multi strong”, and they develop in a multi-polar way, with Shanghai Port being the center. The hinterland of ports is generally stable and locally fluctuated, and the edge hinterland of Shanghai Port gradually shrinks. The comprehensive coordination degree between the ports and the hinterland has an increase trend, and that of Zhoushan Port in Ningbo is the highest.