On the basis of analyzing historical records and field data, the process in the formation of longitudinal profile of the ancient Lower Yellow River channel (1194-1855) has been studied. It is found that the process of profile adjustment can be roughly divided into two stages. In the first stage, the river channel adjusts itself by steepening its slope to match the transportation of sediment load. In the second stage, aggradation raises the profile of the entire Lower Yellow River in order to balance the retrogressive effect of the seaward extension of the river mouth. A close relationship can be set up between the profile raising and the river course extension. The profile of the present Lower Yellow River is quite similar to that of the ancient Lower Yellow River channel and has changed little in the last forty years. It is thus concluded that the present Lower Yellow River has now also undergone a second stage of profile adjustment and the seaward extension of the river has become the main cause of the on-going aggradation in the river channel. Therefore, it is of fundamental importance to reduce the sediment influx into the estuarine area if the aggradation of the present Lower Yellow River is to be mitigated.
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