In this study, the spatial and temporal distribution characteristics of dissolved organic carbon (DOC) concentration in Gehu Lake, Taihu Lake Basin, China, and its influencing factors were studied through annual surveys conducted in 2018 and 2019 to aid its management and restoration. The DOC concentration ranged from 1.92 to 5.60 mg·L^-1, and the average DOC concentration was 3.30±0.78 mg·L^-1. The DOC concentration was highest in winter, followed by spring, summer and autumn; it was significantly higher in winter and spring than in summer and autumn. The DOC concentration was lower in the northern area and higher in coastal areas. Linear fitting showed that DOC concentration was strongly positively correlated with the absorption coefficient of chromophoric dissolved organic matter, the permanganate index, particulate phosphorus and particulate nitrogen (p<0.01) and significantly positively correlated with organic suspended solids (0.01<p<0.05). The photosynthesis of phytoplankton and the input of exogenous organic matter were the most important factors affecting the concentration of DOC in Gehu Lake. These results provide information for the governance of Gehu lakes.