Study of total organic carbon (TOC), total nitrogen (TN), organic carbon isotope (δ¹³C_org), nitrogen isotope (δ¹⁵N) and grain size parameters in the lacustrine sediments of Chaohu Lake reconstructed the changes in the primary productivity of the lake since the Holocene, thus revealing the history of Holocene environmental changes in the Chaohu Lake area. During the early Holocene (10100-8200 cal a BP), higher TOC and TN, gradually increasing δ¹³C_org values amid fluctuations, as well as high δ¹⁵N values and high clay (<4 μm) content indicated higher lake primary productivity, reflecting a warm and wetter climate. During the middle Holocene (8200-4200 cal a BP), the TOC, TN, δ¹³C_org values and clay (<4 μm) content were generally higher but showed a fluctuated decreasing trend; silt (4-64 μm) content increased, and δ¹⁵N values were generally lower but with a large variation, indicating that the primary productivity gradually decreased from a higher level and the climate gradually changed from warm and wet to cool and dry; and the low δ¹⁵N and high TN values of 7300-5800 cal a BP and 4300-3800 cal a BP might be influenced by nitrogen-fixing cyanobacteria, corresponding to the weakening of summer monsoon strength during the climatic events of 7500-7000 cal a BP and 4200-4000 cal a BP, respectively. In the earlier stage of late Holocene (4200-2000 cal a BP), the low values of TOC, TN, δ¹³C_org, clay (<4 μm) content and higher δ¹⁵N values, high silt (4-64 μm) content represented the continued decrease of primary productivity and further shift of climate to cold and dry. The gradual decrease in primary productivity of the lake since the Holocene reflected the gradual weakening of the monsoon, and the gradually decreasing 30°N summer solar radiation was the main factor driving the weakening of the monsoon. In the later stage of late Holocene (2000 cal a BP to present), changes in various environmental proxies showed anomalies that differed from the Holocene environmental evolutionary trends, suggesting that the lake environment and sediments have been influenced by intensified human activities.