Abstract: 【Objective】To explore the community structure and functional feeding groups of benthic macroinvertebrates in Wuyu′er River,Heilongjiang Province,and provide basic data for the protection of benthic macroinvertebrates resources in Wuyu′er River.【Methods】In October 2022,samples of benthic macroinvertebrates were collected from 12 sampling sites along Wuyu′er River. The species composition,community structure and functional feeding group distribution were analyzed,and the health status of Wuyu′er River ecosystem was evaluated using the functional feeding group evenness index（j_FD）.【Results】A total of 713 individuals of benthic macroinvertebrates were collected,belonging to 4 phyla,14 orders,25 families,and 51 species（genera）. The number of aquatic insect species was the most,with a total of 33 species（accounting for 64.71% of the total species）. The total average biomass and total average abundance of benthic macroinvertebrates in Wuyu′er River were 13.39 g/m² and 59.42 ind./m²,respectively. The dominant species were Palaemonetes sinensis,Orthoclidius sp.,Micronecta quadriseta and Chironomus sp.. The benthic macroinvertebrates community in Wuyu′er River could be divided into 4 groups,with very significant spatial differences（Global R=0.80,P<0.001）. The functional feeding groups of benthic macroinvertebrates in river basin were mainly gather-collectors（with a relative abundance accounts for 35.48% of the total species abundance）,followed by shredders,predators,scrapers and filter-collectors,with relative abundance were 25.39%,20.48%,13.04% and 5.61% of total species abundance,respectively. The average functional feeding group evenness index at 12 sampling sites was 0.72.【Conclusion】The functional feeding groups of benthic macroinvertebrates in Wuyu′er River in autumn were dominated by gather-collectors and the overall health status of the river ecosystem was good.

Key words: Wuyu′er River, Benthic macroinvertebrates, Species composition, Community structure, Functional feeding groups, Functional feeding group evenness index