PROBLEM TO BE SOLVED: To provide a grouting agent composition for preventing liquefaction offering a gel substance that has appropriate gelation time, permeates into a ground well, and is highly resistant against deformation and wear, along with a ground improvement method using the same.SOLUTION: A grouting agent composition for preventing liquefaction includes (meth)acrylate metallic salt (A), polyalkylene glycol di(meth)acrylate (B), an oxidizer (C), a reductant (D) and water (E). A total amount of the (meth)acrylate metallic salt (A) and the multivalent metallic salt compound (B) to a total amount of the grouting agent composition is between 5 and 16 mass%, and the reductant (D) contains at least one type of compound selected from among thiosulfate and bisulfite compounds. Also provided is a ground improvement method by an infiltration solidification processing method using the grouting agent composition for preventing liquefaction.SELECTED DRAWING: None
