The Urist Mutuality of Autonomy (MOA) scales is one of the most frequently used method for assessing the quality of object relations. This study examined the characteristics and developmental level of the object representation and relation between level of object relations, severity of psychopathology and copying strategies in psychiatric inpatients, using MOA scale and other variables in the Rorschach. Subjects were composed of 13 borderline personality disorder, 14 schizophrenia and 14 major depressive disorder patients. As a result, borderline patients had a higher MOA score than other two groups and the level of object relations assessed by using MOA scores had positive correlation with the severity of psychopathology, distancing defense, intensity of anger and weakness for emotional control. These results mainly suggest that the MOA scale evaluate not only the severity of the psychopathology, but also the level of object relation, suggesting that low level of object relation is core pathology of borderline personality. Keywords：Rorschach, Mutuality of Autonomy, Object relation, borderline personality disorder.