Abstract: Modulated potassium silicate solution(PS)has been applied widely for the protection of heritage soil in the arid area of northwestern China and obviously succeeded.However,protection of such site soil in the moist area is remained as one of research subjects.Based on the data of laboratory tests,the strengthening effect of PS for soil with relative higher water content is presented in this paper.The soil samples taken from Liangzhu civilization site(3000 B.C.)were modulated to obtain higher water content up to 13％ ~25％ and strengthened by PS infiltration.Some important findings were revealed in the comparison of consolidation and shear strength properties for original and PS strengthened soils.The PS strengthening effect can be observed even for soil with water content as higher as 25%.The PS filtration may increase the consolidation property and shear strength,and the laboratory study revealed some important findings in plasticity-brittleness transition.The test data show,that the PS strengthening may result in the stabilization of soil structure framework and secondary support to the pores.This work should give a support to the further application of PS strengthening technology for heritage site soil.