Abstract: The river-connected water system in Dongting Lake includes the Songzi River, Hudu River, Ouchi River, Tiaoxian River, and their tributaries. These rivers serves as an important link between the Yangtze River. In order to conduct an in-depth research on the changes in the relationship between rivers and lakes, this article used historical maps and satellite remote sensing data from eight periods since the mid Republic of China. The remote sensing interpretation and historical comparison methods were adopted to invert the spatiotemporal evolution characteristics of the river-connected water system. The reasons for these changes were also discussed. The results showed that in the past 90 years, the natural river system in Dongting Lake showed a decreasing trend, with a reduction of 68% in quantity, 28.08% in length, and 39.54% in river network density. The number of artificial river channels significantly increased by8.35 times, 12.07 times, and nearly 10 times for quantity, length, and network density, respectively. The development coefficients of both the river-connected tributaries and the river-connected canal showed an increasing trend, however the degree of increase was different. The former had an increase of 18.84%, while the latter had an increase of 19.00 times. The Huarong River Basin showed a decline by 17.98%, which indicated a worsening water system structure. The main driving forces were the activities of flooding storage and cultivation, blocking and merging tributaries, and reclaiming farmland from the lake. The projects of basic farmland improvement and water system connectivity were also among these influencing activities. This research provided useful materials for river regulation and ecological corridor protection and restoration in Dongting Lake area.