Abstract: The species composition and distribution of aquatic oligo chaetes in 15 waters in the Changjiang River Basin were analyzed in this paper. A ltogether 53 species belonging to 3 families and 27 genera were reported. Among them were 31 species of Naididae, 20 species of Tubificidae and 2 species of Enc hytraeidae. Among the three types of waters, the number of species of oligochaet es in macrophytic lakes, mainstream of the Changjiang River and algal lakes are 36, 34 and 24 respectively. The cluster analysis (Euclidean distances) of specie s and faunal similarity of oligochaetes in 15 different waters were calculated. The results reveal that the aquatic oligochaetes are apparently distributed r egionally, and the total species can be distinctly divided into 6 groups.