Abstract: The river port system in Anhui Province,including six principal ports,is a component part of the port system in the Chanjiang River,and of great importance in regional development and integrated transportation network. This paper, based on regional and comprehensive studies, deals with the basic characteristics and dynamic mechanism as well as the development trends of the lower Changjiang River port system in Anhui Province.By calculating location Quotient of the port system’s cargoes,this paper discusses the characteristics of function of the principal ports. Based on the concerned statistics, the author holds that dominant direction of the flow of freight handed at the principal ports is the Changjiang River. The bulk cargoes handed at the port system have three kinds; 1) mineral building materials; 2) coal and oil; 3) nonferrous and ferrous metal mines,steel. A practical formula of ports unbalance index is designed for determining the spatial distribution of the port system. The spatial difference of the port system between the south and the north banks shall be improved and the structure of size-rank of the port system shall be adjusted.The develompent and changes of the port system could be divided into three stages: 1)embryonic stage (the Spring and Autumn Peroid-the end of the Ming Dynasty and the middle of the Qing Dynasty ;2)initial forming stage (the middl of the Qing Dynasty -the 1950s); 3)forming stage(the 1950s-the 1990s). The dynamic mechanism of the port system is mainly controlled by two laws of regional development. Sne is that the development of ports and hinterlands are mutually interacted, the other in that port and port act on each other.Next 20 or more years,the port system resulting from ports expanding and interacting will speed. This will also improve itself functional,size-rank and sptial struetures.