By using a structured questionnaire, 175 families and 478 psychiatric-mental health related personnels i.e. 194 public nurses, 104 local policemen, and 180 negihborhood workers are surveyed for knowledge of the Metal Health Act especially in involuntary evaluation and compulsory admission to the hospital. The subject's knowledge level of Mental Health Act is relatively low. The percentage of correct answer from different groups of the subject are ranged from 26% to 78%. However, the public nurse group has the highest percentage. The result shows that propaganda for Mental Health Act is inadequate since the law has been enacted. Both mental health worker and lay people are not ckear about the obligation and right of the caretakers (gardians). This study further implies that the knowledge of social resources and process of helping the mentally disturbed hospitalized should be strengthened.