A normal regenerated tissue is formed by exposing to radiation a connective tissue or a supporting tissue originating in an organ to thereby form a feeder layer and then transplanting epithelial cells thereon to form a stratified structure. By conveniently and surely providing regenerated tissue by the 3-dimensional culture with the use of a human-origin normal tissue as a base, it is possible to construct systems for assessing effects and side effects of chemicals such as drugs or assessing sensitivities thereof with the use of regenerated tissues as models of corresponding tissues respectively.