Recently, the institutional abuse has been increasing in Japan. In addition, two abuses were reported by Yamaguchi prefecture. In this paper, we consider that there are common structural factors in the background which the institutional abuse happens. As a result, we understand that there are four important common factors； institutions, staffs of institution, parents, and administrative problems. And these factors affect it compositely each other, and these factors open to the institutional abuse. For the prevention of the institutional abuse, we have to arrange something with the abuse objectively, and it is necessary to manage systematically. It is the awareness of human rights and the improvement of the support skill of the staffs for intellectual disabled persons that are important above all.