<;P>;PROBLEM TO BE SOLVED: To provide a solidifying material for aquatic organisms, enabling its own stable properties to be obtained, to provide a method for producing the same, and to provide a method for producing an amino acid-containing solidifying material. <;P>;SOLUTION: The solidifying material for aquatic organisms is provided, being obtained by mixing aggregate with a solution containing 1.5 wt.% or more of an amino acid and one or more materials selected from at least ultra-quick-setting cement, ordinary cement and a multifunctional setting agent to effect solidification, thus obtaining the objective solidifying material containing 0.09 wt.% or more of the amino acid. <;P>;COPYRIGHT: (C)2009,JPO&INPIT