Input of huge quantities of sediment discharged to the sea and change of the lower course of the Huanghe River cause great changes in coastal and submarine geomorphology and sand movement. The sand spit on the Huanghe River mouth extended 40 km to seaward from 1976-1996. The sand spits extending velocity is 2.1 km/a at present, and its front is less than 50 km from the east and south coast of the Laizhou Bay. If it continuously extend for some ten years, this part of Laizhou bay will become a lagoon. By that time, the marine ecology environment will change largely and the Xiaoqinghe River mouth and adjacent harbor will be silted. Many ports have been built on the Huanghe River delta coast and adjacent areas. The continued extension of the river mouth spit, wrong choose of inlet position, untimely use of the rivers lower course, any and all of these will affect to construction of ports there. The Huanghe River changed its lower course and emptied into Laizhou Bay from the Qing 8 branch in Aug. 1996. When the lower course started to change, the inlets direction of the main axis was N81°30’E. However, two months later, it extended NW. Sandy sediment discharged from the Huanghe River transported along shore to NW and turbidity water with fine sediment reached the vicinity of Dongying Harbor. In order to decrease the influence of sediment discharged from the Huanghe River on coastal ports in the adjacent coast, it is necessary to scientifically choose the position of the inlet, correctly control the use time of the rivers lower course, and change the direction of inlet in due course.