A sediment core (HL16) was collected in the central part of Lake Hulun in northeastern Inner Mongolia using a piston core sampler. The total organic carbon (TOC) content and its stable isotope (δ¹³C_org), total nitrogen (TN) content and the total organic carbon and nitrogen (C/N) ratio of sediments were analyzed to investigate the temporal changes of organic carbon burial and its driving factors, as well as the organic carbon (OC) sources over the mid-Holocene. The OC burial rate presented an overall increasing trend for the last 7400 years, and the average OC burial rate was about 2.06 g/(m²·a), with a total C pool of 35.25 Tg C. Relative contributions of allochthonous and autochthonous OC input were estimated using a binary model, suggesting that OC being buried in Lake Hulun was mainly generated from terrigenous vegetation. The binary model also revealed that autochthonous OC demonstrated an increasing trend in the last 1000 years. The OC burial rate was negatively linked to temperature and precipitation based on Pearson analysis, implying that the increase in temperature and precipitation might lead to the decrease of OC burial in Lake Hulun in the long term scale.