Polymer gel containing biocompatible material, dry gel, and process for producing polymer gel

The polymer gel obtained from the method for incorporating hydroxyapatite in a polymer hydrogel by impregnating an aqueous phosphoric acid alkali metal salt solution and an aqueous carbonate solution alternately one or more times with a polymer gel consisting of a polymer of a water-soluble organic monomer and a water-swelling clay mineral, contains finely dispersed biocompatible substances, and the polymer gel excels in dynamic physical property and stability and can exhibit the performance of the biocompatible substance efficiently. The dried biocompatible substance-containing polymer gel is obtained by drying the above polymer gel.