Inmates have challenged a host of institutional conditions as being in violation of cruel and unusual punishment in Korea. The purpose of this study is to promote rationally tools of restraint (handcuffs, chains, irons, strait-jacket) in jail. Thereby, it attempts to provide several ways for improvement of tools of force and application of restraints on inmates. This study reviews existing precedents about tools of restraint in Korea. and investigates the prison rules in the United Nations, the United States, Germany, and Japan. The efficient alternatives proposed in this study are as follows; pre-prevention of accidents in prison(suicide, assault, self-injury, escape, disturbance, and so forth) through classification of inmates and counselling, development of new restraint tool, application of closed circuit television, development of restraint tool manual, observance of proportion law rule.