Abstract: Rivers are one of the main pollutants sources of seashores and influence the water environmental quality in the north China Sea significantly. However, just a few rivers into the sea are covered by routine monitoring in Liaoning Province. Therefore, a total of rivers in the sea along the coast of Liaoning Province were investigated and sampled and analyzed one by one. In combination with the routine monitoring data of the seashore sites which were the nearest to the estuary, the water quality of rivers into the sea and their influence on the seashores were analyzed by correlation analysis and principal component analysis. At the same time, the risk assessment of typical heavy metals (Pb and Hg) was carried out. The results showed that the concentration of pollutants of rivers into the sea is much higher than that of the seashores, which should be a threat to the water safety of the seashores. The ecological risks of Hg in the seashores of Huanghai Sea and Bohai Sea were mainly at no risk and low risk, while the rivers into Bohai Sea were at medium risk, basically distributed in the rivers into Bohai Sea. The ecological risks of Pb in Huanghai seashores and the corresponding rivers were at no risk, but Liaodong Bay and the corresponding rivers were at medium-high risk. Therefore, the management for pollutants into the rivers should be strengthened to improve the water quality of the seashores, especially for organic matter, nitrogen and phosphorus into Bohai seashores. The focuses should be on the control of domestic wastewater and agricultural non-point pollution, so as to improve the water quality of the seashores.