Abstract: The Changjiang's course at its estuary is divided into two brauches by the Chongmitg Island. According to the historical records of channel changes in the reaches of the Changjiang's estuary, the feasibility of the project of sealing up north branch is discussed in this paper. The author indicates that the project the would be advisable to realize as it would, be help-ful to mitigate channel siltatiou and sea water intrusion in the area of the Changjiang's estuary after completion of the project of nouth to uorth water transfer from the Chang-Jiang's downstream.