PROBLEM TO BE SOLVED: To provide a plastic injection material in each of whose constituents (mixtures) an increase of the viscosity thereof can be suppressed while decreasing a flow value of the plastic injection material just after produced.SOLUTION: The plastic injection material is obtained by mixing a first mixture, which contains a latent hydraulic material and water, a second mixture, which contains attapulgite, a phosphate-based mixing agent and water, and a third mixture, which contains a hardening auxiliary material capable of hardening the latent hydraulic material and water.SELECTED DRAWING: None