The construction of the Three Gorges Dam has caused significant changes in aquatic ecosystems. Benthic macroinvertebrates, an important component of aquatic ecosystems, have also been greatly affected by reservoir impoundment. In order to explore the impact of impoundment on their community in tributaries of different hydrological regimes and the role of tributaries in their resource production, benthic macroinvertebrates were investigated in four tributaries (Lixiang River, Yulin River, Quxi River and Longhe River) of the Three Gorges Reservoir in July 2015 and January 2016. In particular, their community, species diversity, and relationship with environmental factors were studied. It was found that (1) In July, a total of 655 benthic macroinvertebrate individuals belonging to 59 species were collected. Among these, 40 individuals (4 species) were collected in the river reaches affected by reservoir impoundment, with Macrobrachium nipponensis being the dominant species comprising 57.5% of these 40 individuals. However, in January, a total of 1123 benthic macroinvertebrates belonging to 69 species were collected. Among these, 238 individuals (16 species) were collected in the river reaches affected by the reservoir impoundment, with Neocaridina denticulata being the dominant species comprising 14.2% of these 238 individuals. (2) No significant differences in the density, biomass, and species diversity of benthic macroinvertebrates were found between the river reaches unaffected and affected by reservoir impoundment in the tributaries periodically affected by reservoir impoundment. However, in the tributaries continuously affected by reservoir impoundment, the biomass of benthic macroinvertebrates in the river reaches affected by reservoir impoundment was significantly lower than that of the benthic macroinvertebrates in the river reaches unaffected by reservoir impoundment (P < 0.05). Furthermore, the Shannon-Wiener diversity index and Margalef species richness index in the river reaches unaffected by reservoir impoundment were significantly higher (P < 0.01) than those indices in the river reaches affected by reservoir impoundment. (3) The canonical correspondence analysis (CCA) showed that, in July, the main environmental factors affecting the benthic macroinvertebrate distribution were water depth, current velocity, water temperature, dissolved oxygen content, specific conductance, and nitrate concentration (NO₃^-). In January, the main environmental factors were water temperature, dissolved oxygen content, total phosphorus (TP), current velocity, water depth, specific conductance, and transparency. These results indicated that the community and species diversity of benthic macroinvertebrates could be affected by reservoir impoundment, and the tributaries play an important role in their conservation. In the tributaries continuously affected by reservoir impoundment, significant differences in the richness and abundance of benthic macroinvertebrates exist between the river reaches unaffected and affected by reservoir impoundment; however, in the tributaries periodically affected by the reservoir impoundment, no significant differences were found.