Voluminous studies have been recorded in the world literature on rheumatoid arthritis. Yet, to this day many of the problems in diagnosis and treatment remain unsolved. To make the matter more complicated, many unusual, hitherto unfamilial cases of joint trouble have been reported since the advant of steroid hormones and possess as a new challenge to orthopedic surgery. This is particular true in Korea. The author analyses 193 consecutive rheumatoid arthritis seen in the Out-Patient Clinics of the Seoul National University Hospital during the period Jan. 1955 through July 1967. 1. According to Classification of American Rheumatism Association, 62 of the 193 cases (32.2%) were classic and definite rheumatoid arthritis and 131 cases(67.8%) probable and possible rhumatoid arthritis. 2, There were 142 female patients as compare to 51 male patients, are ratio of almost 3 to 1. 3. The age group 21 to 30 years occupied to 35.8% in this series. 4. 112 cases visited clinic within one year after onset of symptoms. 5. 85.5% of the cases had recurrences more than twice. 6. Muscle atrophy, joint deformities and ankylosis were observed in 34 cases but the remainder appeared normal. 7. Joints were involved symmetrically in 30%, while more than two joints were involved in 78.2% of the cases. The Joints involved in order of frequency were as follows: the knee. ankle, wrist, proximal interphalangeal joints of the hand and the elbow. 8. Of the 84 cases in which Latex fixation test was performed positive reaction was present in only 34 of cases, or 40.5%. 9. Of the 132 cases in which routine C B C was ordered, 60% showed increased ESR, 37.8% leukocytosis, and 34.2% anemia. 10. Of the 17 cases in which synovial fluid was aspirated ten revealed increased in protein content of more than 4 gm/100 cc. Increased in leukocyte count of more than 3000/mm3 was encountered in all the cases tested. 11. In only one case was the diagnosis confirmed by biopsy. 12. 60.6% of the cases had used steroid hormones irregularly prior to initial visit. Some formed of side effect were observed in 17 cases.