Pit construction in loosely filled ground consisted of construction garbages , mineral wastes, etc. owing to its nonhomogeneity and large pore rates，is one of the most difficult problems in the waterproofing engineering. Based on the features of deep filled strata, strong permeability and plentiful underground water supply, the design , construction method and effects on chemical grouting for waterproofing in the zone B of Changjiang square are briefly introduced in this paper.