The diatom communities of Hejiang River, a branch of Xijiang River, Pearl River basin were evaulated by means of two-way indicator species analysis and detrended correspondence analysis. The diatom indexes of Generic Diatom Index(IDG), Biological diatom index(IBD), Specific Pollution sensitivity Index(IPS) and Trophic Diatom Index(TDI) were then further used to validate the conclusion. According to TWINSPAN, the 38 sampling sites of Hejiang River were classified into 4 types, the quality of ecological habitat and human disturbance were getting worse and worse from community Ⅰ to community Ⅳ; the obvious boundaries of four communities existed on DCA ordination diagram, the ecological value of Van Dam showed that water environmental pollution gradually increased from Ⅰ to Ⅳ, the controversial samples of 7, 8 and 24 tended to community Ⅲ on DCA ordination diagram. The results indicated that the divided diatom communities can better reflect the ecological quality, in addition, IBD, IPS, IDG can be applied for monitoring and evaluating rivers in Hejiang River.