Abstract: The effects on part functions of ecosystem services from silt deposit and reclamation were studied in this paper.The results show that silt deposit,reclamation,and wetland have the relationship of mutual condition,mutual reason-result and the mutual circulatory cause-and-effect.And the circulatory cause-and-effect relationship,therefore,forms the 3 ecological chain-reacting，i.e.silt depositwetland swellingoncomelania hupensis breeding,rat breeding,land deteriorate;silt depositwetland reclamationreducing of bio-resources;silt deposit and land reclamationfunction reduce of water conservancythe frequency of flooding,water pollution,the blocking of navigation lane.All of the chains weaken and/or do harm to the functions of lake services,and further reduce part of their value,namely the losses of aguatic product resources,of saving and supplying water,of adjuting and saving and biology diversities,of ecology environment and shipping,reaching 3210 million yuan,153 million yuan,4192 million yuan and 7476 million yuan respectively,with appropriate estimation of the potential value.