Abstract: Based on the monitoring data collected of benthic invertebrate from the 24 sampling sites, a preliminary Benthic Index of Biotic Integrity (B-IBI) was developed to assess the health status of main stream and tributaries in Dongjiang Watershed. Totally 30 candidate metrics which related to benthic's community structure and function, feeding function, interference tolerance and habitat were evaluated by distributing range analysis, sensitivity analysis and Pearson correlation analysis. The final B-IBI included total taxa number, EPT taxa number, relative abundance of EPT taxa, three most-dominant taxa, scrapers and gathers. The dimension of the core metrics were unified by rationing and the scoring normalized based on the quadrisection system, and these scores were interpreted as health (387), sub-health (290-387), normal (193-290), poor (097-193) and very poor (097). The results showed that in the whole Dongjiang Watershed 292% of sampling sites were in health and sub-health conditions, 292% of sampling sites were in normal conditions, and 416% of sampling sites were in poor or very poor conditions.