Compulsion becomes long-term when treatment is commenced with very severe resistance. Patients showing emotional changes are rare compared to those with conversion and phobic disorders. However, most people improve when careful treatment is carried out. Although there are those in whom drug treatment is effective,drug treatment and psychotherapy are concomitantly used in most cases. In this lecture, the characteristics of compulsion were psychodynamically investigated regarding : 1.Central conflict, 2.Defense mechanisms, 3. Condition of love life（including sex life）, 4. Growth history, by comparing with phobias. When the life of the inner-self protrudes, obsessive-compulsive patients try to contradict and deny this. The symptoms sometimes directly represent the mental conflict of the person, and sometimes the symptom formation process may be understood to some extent. It is said that such cases are suitable for psychotherapy. Psychodynamic psychotherapy involves regaining the continuity of emotional life divided due to defenses such as negation,reaction formation, and isolation. Meanwhile, the real nature of phobias is avoidance and escape. Therefore, the trick in proceeding with interviews is to lead the phobia patient to areas which they avoid during interviews and areas which they avoid in daily life, and to have the patient enter these fields at times by encouraging them.