The river-lake relationship between Huaihe River and Hongze Lake was systematically studied. The river-lake relationship was proposed based on the exchange of water and sediments, including the evolution of rivers, lakes, deltas entering the lake, and changes in the volume of adjustment of Hongze Lake, the evolution of the river out of the lake and discharge capacity. The historical research and evolution process of the river-lake relationship was also explained. In addition, the current status of the river-lake relationship was analyzed. Based on above research, the research trends of river-lake relationship was viewed. More theoretical and technical conditions needs to be established to the study of river-lake relationship.