Abstract: To explore the influence of nutrient sources on the beta-diversity patterns of macrozoobenthic communities in plateau lakes, a quantitative survey of macrozoobenthos and their nutrient sources was conducted in the Zhaling Lake and Eling Lake Basins from 2022 to 2024 in the dry and wet seasons. A total of 108 taxa belonging to 8 orders, 39 families were collected. Overall, the lake, habitat, season, and their interactions showed no significant effects on zoobenthos species richness(P>0.05). However, total beta-diversity was relatively high and primarily driven by turnover component. We used parameters in water (chlorophyll a, phytoplankton, total nitrogen, total phosphorus) and catchment characteristics (vegetation coverage, altitude differences, precipitation) to quantify allochthonous inputs and autochthonous nutrients. The Chl.a was significantly higher in the wet season than that in the dry season (P<0.001), and the allochthonous input in the littoral zone of Eling Lake was significantly higher than that in the river region (P<0.01). The Random Forest model indicated that allochthonous nutrient had a stronger correlation with the beta-diversity of the macrozoobenthic community. Allochthonous inputs outweighed autochthonous nutrients in both river and littoral zones during the wet season. In contrast, during the dry season in littoral zone, the importance of autochthonous nutrients such as chlorophyll a and total phosphorus increased significantly, revealing a co-dominant pattern driven by internal and external sources. The total beta diversity and its turnover component exhibited greater sensitivity to allochthonous input, while nestedness in river zone during the wet season also showed certain responsiveness to autochthonous nutrient. These findings provide fundamental scientific support for the ecological management of plateau lake ecosystems.