Aiming at the problem that the current commonly used indicators of river system connectivity can hardly present the coinfluence of river system structure change and dynamic dam regulation simultaneously, a new indicator of the connectivity of the river system （gated node ratio and gated connectivity） which integrates the dual influence of the river system structure and dynamic dam regulation was proposed on the basis of analyzing the limitations of the commonly used indicators.The advantages of the new indicator are analyzed through case analysis, and the new indicator were applied to the analysis of the spatiotemporal evolution characteristics of the river system connectivity in the Qhuai River Basin during three typical periods of wet, normal, and dry seasons in the 1960s, 2009 and 2016.The results show that the sluicenode ratio and sluice connectivity overcome the shortcomings of the current commonly used indicators, and can not only reflect the differences caused by the changes in the river system structure, but also capture the dynamic impact of the changes in the frequency of sluice gate opening.The connectivity of the river system in the Qinhuai River Basin from the 1960 to 2016 has shown a significant downward under the combined effect of river structural simplification and the massive construction of sluice dams, but the decline varies in wet, normal, and dry seasons. The decline was smallest in flood season because the increase in the frequency of gate opening mitigated the negative impact of rising gate numbers on the connectivity of the river system. In contrast, the lower frequency of gate opening in dry season highlighted the negative impact of increasing gate numbers, leading to the greatest decrease.The evolution of hydrological connectivity in the 17 subbasins within the basin shows significant heterogeneity. The old urban area of Nanjing, Jiangning District and the central development zones of Juren City are significant areas of reduction in hydrological connectivity, mainly due to multiple factors such as urbanization, dam quantity, and opening frequency, but the dominant factors vary.