The effects of eutrophication on the energy flow and material flow for lake ecosystems need to be studied. Most of previous studies showed the impacts of eutrophication on the structure and function of lake food web, while the influences of eutrophication on the nitrogen and carbon sources for consumer communities were limited. In view of this, the largest shallow eutrophic lake in North China Plain—Lake Baiyangdian was selected as the study area. According to the physical-chemical parameters in water and sediment, the Lake Baiyangdian was subdivided into three habitats(Habitat 1 strongly influenced by wastewater discharge(Sites Ⅰ and Ⅱ), Habitat 2 influenced by aquaculture and densely populated villages(Sites Ⅴ, Ⅶ and Ⅷ), and Habitat 3 influenced the least by human disturbances (Sites Ⅲ, Ⅳ and Ⅵ)). In April and August 2018, the samples for pelagic organisms, benthic organisms and fish were collected, respectively. Carbon and nitrogen stable isotope techniques were used to quantitatively calculate the contribution percentage of benthic and pelagic organism for the carbon and nitrogen sources of consumer communities. The results showed that: 1) according to the seasonal variation of water and sediment parameters, except pH, the values of chemical oxygen demand (COD), Ammonia nitrogen in sediments (NH₃-Ns), total nitrogen (TN), and total phosphorus in sediment (TPs) in April were higher than that in August, while the other parameters were existed higher values in August; in terms of spatial distribution, temperature (T), water depth (WD), dissolved oxygen (DO), total carbon in sediments (TCs) were showed the highest values in Habitat 3, while the other parameters were showed the highest values in Habitat 1; 2) According to the spatial distribution of δ¹³C and δ¹⁵N, for the same populations, the degree of enrichment were appeared significantly different at three habitats; while for the seasonal variation, the values of δ¹³C for the consumer communities showed significant difference, while the values of δ¹⁵N without significant difference; furthermore, the δ¹³C and δ¹⁵N of the consumer communities were existed the negatively correlated; 3) According to the spatial distribution of consumer trophic level (TL), the TL was appeared significantly different at three habitats; for the same consumer community, the highest values were appeared in Habitat 1, while the lowest values were appeared in Habitat 3; in terms of the temporal variation, the TL was not existed the significantly difference; 4) For the pelagic organisms, the contribution percentage for the carbon and nitrogen sources of consumer communities were appeared higher values in April, and the highest values were existed in Habitat 1; while for the benthic organisms, the contribution percentage for the carbon and nitrogen sources of consumer communities were appeared higher values in August, and the highest values were existed in Habitat 3; 5) Through correlation analysis, the results showed that the δ¹³C of consumer communities were appeared the negatively correlated with TP, TCs, TN in sediment (TNs), total organic carbon in sediment (TOCs), TPs; while the δ¹⁵N were existed the positive correlation with TP, TCs, TNs, TOCs, TPs. Therefore, the eutrophication can influence the carbon and nitrogen sources for consumer communities, and change the energy flow and material flow for the lake ecosystem.