[Aim] To understand the characteristics, origin, taxonomic affinities, and damage of the known invasive alien plants in Chengdu, and to provide scientific decision-making basis for their management.[Method] Species list and distribution information were obtained through field investigation, specimen records, and literature study. The floristic composition were calculated and analyzed.[Result] A total of 158 invasive alien species (including subspecies and varieties) were identified, belonging to 110 genera in 42 families. The families with the highest number of species were Asteraceae (36 species), Fabaceae (17 species), and Poaceae (13 species), accounting for 41.77% of all the species recorded. The genus with most species was Amaranthus (8 species). One hundred and one species are native to America. According to the level of invasiveness, each species was classified into one of 5 categories:19 species of agressive invasive plants (grade 1), 32 species of serious invasive plants (grade 2), 20 species of local invasive plants (grade 3), 41 species of general invasive plants (grade 4), and 46 species requiring further analysis (grade 5). Most invasive alien plants in Chengdu had a pantropical distribution, tropical Asia-tropical America disjunction, or showed worldwide distribution.[Conclusion] The number of invasive alien plants have increased significantly, and the spreading trend has intensified in Chengdu. Finally, this article puts forward four prevention and control suggestions, which are establish a risk assessment system for invasive alien plants, carry out research and development of prevention and control and utilization technology, introduce cautiously and strengthen popular science education for preventing the invasive alien plants.