The main river course of Xijiang in the Zhujiang delta is characterized byalluvial process and closely connected with the evolution of the delta.Withregard to the fluvial process of the reach in recent period,only the threefollowing problems will be discussed in this paper:(1) The profile of the river bed has a very gentle gradient and greaterundulation in elevation.This is the result of interaction of many factors suchas hydrodynamics,sediments and boundary of the estuary during a long developing period of the delta thro ugh deposition.(2) The characteristics of deposition and erosion of the river are primarily demonstrated in:1.The cross section of the bed is more stable than theprofile.2.The secular trend of deposition interrupted by a short period oferosion and deposition.3.There are seasonal changes with erosion occurring inflood season and deposition in dry season.4.The cross section of the mouthtends to become narrower and deeper gradually.5.An adjustment of river hasoccurred due to the projects of the joining dykes and constructing sluices,landreclaimation from the sea and the controlling engineering of the mouth.(3) The oncoming sediment of Xijiang basin is the primary source ofthe material in forming the subaqueous delta offshore.For the present,thedelta is extending towards the Continental shelf.