Abstract:【Aim】 In response to a desire to prevent and control the spread of alien invasive species (AIPs) in the lower reaches of the Jinsha River, this study focuses on the reservoir areas of Wudongde and Baihetan Power Stations in the mainstream. This study aimed to elucidate the species composition and invasion status of AIPs and investigate the presence of alien invasive plants in these reservoir areas. Additionally, in this study, the risk of invasion was assessed to support the prevention of the expansion of alien invasive plants, as well as to enhance the ecological security in the study area. 【Method】 We conducted a comprehensive analysis of AIPs using a combination of transects, sample survey methods, and a literature review. A hierarchical analysis was employed to establish a risk assessment system for AIPs. The system evaluates the invasion process, status, associated hazards, and prevention and control measures. Finally, the invasion risk level was determined based on the grading standards. 【Result】 Based on the results, a total of 103 documented AIPs across 70 genera and 28 families were identified. Among these, five alien invasive plants were categorized as level Ⅰ risk, 12 as level Ⅱ risk, 24 as level Ⅲ risk, 28 as level Ⅳ risk, and 34 as level Ⅴ risk. 【Conclusion】 While numerous species of AIPs were found in the reservoir areas, the majority fell within the low-risk levels (Ⅳ, Ⅴ), posing minimal harm. However, 17 invasive alien plants were categorized as high risk (Ⅰ, Ⅱ). Thus, we recommend prioritizing the prevention and control measures for these high-risk alien invasive plants to minimize threats to the ecological security of the Lower Jinsha River.