The contents of dissolved organic carbon (DOC) and the flow of Yichun River were determined and the spatial and temporal variations in DOC content and flux were studied. It was found that in the summer, DOC is originated primarily from the allochthonous sources and the content of DOC increases downstream. There is a synchronous fluctuation of DOC contents and flow with a 8 hour delay of the former. A hyperbolic equation can fit the data well and is able to predict the DOC content and flux based on flow measurements. During the winter season when the river is totally covered by ice, the autochthonous source becomes dominant and the DOC content is negatively correlated to flow due to dilution effect. The DOC flux of the river was calculated to be 7 113 ton/yr, or 2.88 gC/m²穣r, among which over 90% occurs during the 5 months in the wet season.