Five hundred normal boys and girls under the age of 20 years were observed to evaluate the normal angles of the pelvis and hip as well as the chronology of postnatal ossification and growth plate fusion in the proximal femur and pelvis at the various age groups with the pelvis AP X-ray films during the period of 3 years from June, 1978 to May, 1981 at Severance hospital. The results were as follows: 1. The appearance of the ossification center of femoral head occurred at age 2 to 9 months in boys, 1 to 7 months in girls and its fusion occurred at age 15 to 19 years in boys, 14 to 18 years in girls. 2. The appearance of the ossification center of greater trochanter occurred at age 2 to 5 years in boys, 2 to 4 years in girls and its fusion occurred at age 15 to 19 years in boys, 14 to 17 years in girls. 3. The appearance of the ossification center of lesser trochanter occurred at age 7 to 13 years in boys, 6 to 12 years in girls and its fusion occurred at age 15 to 19 years in boys, 13 to 18 years in girls. 4. The fusion of triradiate cartilage occurred at age 13 to 18 years in boys, 12 to 15 years in girls. 5. The appearance of the ossification center of ischial tuberosity occurred at age 13 to 18 years in boys, 12 to 17 years in girls and its fusion began at the age of 19 years in boys, 18 years in girls. 6. The appearance of iliac apophysis occurred at age 13 to 18 years in boys, 12 to 16 years in girls and its fusion began at the age of 19 years in boys, 18 years in girls. 7. The fusion of the junction of ischial and public rami occurred at age 5 to 12 years in boys, 4 to 12 years in girls. 8. The appearance of the teardrop of Kocher occurred at age 3 to 9 years in boys, 3 to 8 years in girls. 9. The value of acetabular angle and iliac was decreased according to the increment of age, but the value of C-E angle was increased with age. 10. The acetabular angle in the 0-2 months group, 11-12 months group, and the groups over 3 years, the C-E angle in the groups over 7 years, and the iliac angle in the 0-2 months group, 5-6 months group, and 7-8 months group showed a difference between males and females.