Abstract: Yilong lake is one of the nine plateau lakes in Yunnan Province, China. It is a typical plateau lake on the node of evolution from plant-type lake to algae-type lake. For historical reasons, the water environment conditions in Yilong lake are completely different between the East and West areas, which is a good representative plant-type and algae-type Lake in Yunnan Plateau. There have been few research results on submerged plants in Yilong lake since 1980. To address this issue, in this study, the water quality and submerged plants of Yilong Lake are investigated for one year period, the distribution of submerged plants and their relationship with water environment factors are also studied, with aims to leave precious historical data for the study of submerged plants in Yilong lake and explore the distribution and impact factors of submerged plants, provide data and technical support for submerged plant restoration. Furthermore, results indicate the spatial distributions of submerged plants are significantly different between the East and West Lake areas with the dominant species of Najas minor, Utricularia vulgaris and Hydrilla verticillata in the West Lake area while potamogeton pectinatus and Myriophyllum verticillatum in the East Lake area, the coverage, biomass and species richness of submerged plants in the West Lake area are significantly higher than that in the East Lake area. Meanwhile, the results of correlation analysis show that water depth, transparency and dissolved oxygen are the main environmental factors affecting the distribution of submerged plants in Yilong lake, while total nitrogen, total phosphorus, ammonia nitrogen and pH are the secondary factors. Different restoration strategies should be adopted and different submerged plant species should be selected for restoration in different lake areas.