Dissolved organic matter (DOM) plays a pivotal role in aquatic ecosystems and biogeochemical cycles. Understanding the composition characteristics, sources, and influencing factors of DOM in typical lakes and reservoirs across northern China is crucial for effective organic matter pollution control and ensuring safe water transfer. This study collected 130 surface water samples from eight representative water bodies: Xiaoxingkai Lake (XXKH), Songhua Lake (SHH), Dahuofang Reservoir (DHF), Guanting Reservoir (GT), Yuqiao Reservoir (YQ), Baiyangdian Lake (BYD), Hengshui Lake (HSH), and Nansi Lake (NSH). The key findings are as follows: (1) Through parallel factor analysis (PARAFAC), three distinct fluorescent components were identified in the DOM of these lakes and reservoirs: humic-like substances (C1), tryptophan-like substances (C2), and tyrosine-like substances (C3). DOM in northeastern lakes and reservoirs exhibited strong humification characteristics with relatively low autochthonous contributions, while those in North China demonstrated pronounced autochthonous features. Notably, BYD displayed unique DOM characteristics with higher DOM content and protein-like components compared to other studied water bodies. (2) Humic-like substances from anthropogenic sources significantly positively correlated with COD and HIX (p < 0.01). Protein-like components (C2, C3) showed significant positive correlations with DOC, FI, and BIX (p < 0.01), but negative correlations with HIX (p < 0.01). DOM components correlated more strongly with nitrogen than phosphorus nutrients. (3) Environmental factors significantly influenced DOM dynamics. Larger drainage areas prolonged DOM retention time, promoting the accumulation of autochthonous DOM components. Greater water depth facilitated DOM preservation. Elevated temperatures enhanced DOM transformation within lakes, strengthening autochthonous characteristics while weakening allochthonous features. In high-precipitation regions, terrestrial humic substances were transported into water bodies through runoff, enhancing exogenous DOM characteristics. Biological factors, including algae, aquatic vegetation, and microorganisms, primarily influenced DOM dynamics through endogenous processes, collectively regulating nutrient cycling and ecological functions. In areas with intensive human activities, increased endogenous DOM production was observed in lake and reservoir waters. Furthermore, regions with higher vegetation coverage contributed more humic-like components to aquatic systems. This comprehensive analysis provides valuable insights into DOM dynamics in northern China"s lakes and reservoirs, offering scientific basis for water quality management and pollution control strategies.