It is important to keep patient safety in the medical environment, and it is also necessary to provide quality of care. However, the issues of suicide and self-harm behavior have been neglected in hospitals, and the investigators are lacking of effective preventive interventions and policy. There are many topics related to patient safety in medical environments, including mistakes happened during the process of giving medicine, falling, environment safety. However, suicide behavior among inpatients has been posing the greatest challenge to medical personnel. According to the Taiwan Patient-Safety Reporting System (Taiwan Joint Commission on Hospital Accreditation, 2009), there were 1,613 accident events of hospitalized patients in 2008. General wards are the mainly location of events, in the categories of events, 12.0% is self-harm behavior. Although there are only 43 events of suicide attempt, its consequence are the most serious compared to other patient safety issues. Researches in the 1960s in western countries indicated that the death rate of suicide among hospitalized patients are 0.06~5.66 per thousand. Even suicide is a rare topic, the investigators cannot ignore its severity. To prevent suicide events, psychiatric ward and general ward should put emphasis on the prevention, the education training and communications between patients and nurses (Taiwan Joint Commission on Hospital Accreditation, 2009). For general medical workers, they might underestimate the formation and the effects of suicide or self-harm behavior. The investigators may reach the goal of suicide prevention and treating for self-harm behavior appropriately if clinical nurses can identify the high risk group of suicide effectively and follow the steps suggested in the gatekeeper program.