Personality characteristics of TMJ dysfunction patients was studied by means of MMPI test. 100 TMJ dysfunction patients and 100 healthy controls were subjected at the Department of Oral Diagnosis and Oral Medicine, Pusan National University Hospital, during the period from March 1983 to February 1985. All the patients were divided into 2 groups namely, acute group and chronic group by duration of path and discomfort problems for 6 months or longer. The obtained results were as follows : 1. Mean value of T-scores on each clinical scale was within normal range in both patient and control group. 2. There was significant difference in scales of Hs, D. Hy, Pt, Sc and IR between patient and control group. 3. As compared with control group by sexual subclass, scales of Hs, Hy and Pt of both sex, scales of Sc and M-DI of male and scales of D of female in patient group were significantly higher than those in control group 4. The longer was duration of TMJ problems, i.e., in increasing order of control, acute and chronic group, the higher was mean value of T-scores on scales of Hs, D, Hy, Pt, Sc, IR and M-DI. 5. Mean values of T-scores on scales of Hs, D and Hy were the highest in all the clinical scales of total class and subclasses(i. e. male group, female group, acute group and chronic group) with TMJ dysfunction and showed 1-:i-2 (Hs, -Hy, -D. ) profile pattern, conversion "V.ot;V.