Abstract: There are vast non-consolidated alluvia deposits freshly formed in estuary area of Yangtze River and nearby coastal area.The deposits contribute to land subsidence.Based on their distribution,two subsidence volumes of different kinds of deposits are respectively calculated due to their consolidation and underlayer soil consolidation.It is found that the subsidence induced by the deposits has a larger ratio of the total surface subsidence.And also the suggestions for the in-depth study on deposits are discussed in this paper.