Abstract: Based on PAHs contents in the sediments of the main stream and tributaries of the Yellow River, the distribution characteristics of PAHs were analyzed. The results show that the contents of PAHs are higher in sediments of tributaries than that of main stream of the river, with the order of the Yiluo River > the Fen River > the Mang River. According to the varieties and aromatic rings distributions of PAHs, petroleum-derived contamination may be the dominant source in the tributaries of the Yellow River while some PAHs in the Yiluo River may be derived from pyrolytic source. The risk assessment values for organic pollutants in the sediments show that the three tributaries are at high ecological risk region, which might exert significant potential damage to the organisms in the region.