Abnormal pelvic configuration with resultant abnormal value of acetabular angle, iliac angle and iliac index is well known in some congenital and hereditary diseases and its measurement is valuable in establishing diagnosis in these diseases. Considering that there is no available standard values of Korean children, we measured acetabular angles, iliac angels and iliac indices in 150 normal Korean children, 10 cases of congenital dislocation of hip and 2 cases of mongolism. The results are as follows: 1. The values of acetabular angle, iliac and iliac index are significantly lower than those of American children. 2. Significant increase in acetabular angle is observed in patients with congenital dislocation of hip and significant decrease in iliac index in patients with mongolism is observed. 3. Iliac index seems to be more reliable than either of acetabular angle and iliac angle in the detection of abnormal pelvic contuor in patients with mongolism. We considered that the pel ic mensuration should be done in large number of normal and patients and further study in this fields should be carried out.