Abstract: Evaluating the connectivity of river and lake systems is important for implementing the regional water network connectivity strategy, improving the regional water resources coordination, deployment and carrying capacity, and restoring and improving the water ecological environment. In this study, river and lake systems in the Jianghan Plain are taken as the object, and the improved graph theory method considering the barrier effect of gates and dams and the hierarchical analysis method based on multidimensional connectivity mechanism are adopted. The current situation and factors influencing the connectivity of river and lake systems are analyzed and evaluated in terms of network structure and connectivity function.The results show that:（1）The structural connectivity of the water network in the study area is 0.717 2, which is in the “good” level, but the spatial distribution is uneven, with higher connectivity in the west and east, lower connectivity in the middle, and higher connectivity in the Tongshun River area than in the Four Lakes area；（2）The functional connectivity of the water network in the study area is 0.688 5, which is in the “good” level. Mainly affected by the number of regional irrigation and drainage gates, the high degree of control and the long closing time, local areas such as the Four Lakes Main Canal, the Tongshun River and Hong Lake have poor water flow and low connectivity；（5）The results of structural and functional connectivity evaluation are basically consistent, and reliable and applicable are the evaluation methods, which can provide some reference for the adjustment of water network engineering system and ecological river-lake connectivity system construction in Jianghan Plains.