There are some controversies on the mechanism of the lumbar disc degeneration and disc prolapse. But,it is clear that many factors are related to the disc degeneration. Configurations of the lower lumbar and lumbosacral spine have long been proposed as one of the important factors of disc degeneration in these areas. To look for the configurational risk factors and the probability of disc degeneration by the combinations of these factors, we analyzed simple radiographs and MRI of 73 patients who complaints of low back pain and are between 20 years and 39 years of age. We performed chi-square test and multivariate logistic regression analysis: L4-5 disc degeneration and L5-Sl disc degeneration as dependent variables and lumbar lordosis, sacral inclination, height of intercrest line, transitional vertebra and facet joint asymmetry as independent variables. We could not find any of these variables significantly related to the L4-5 intervertebral disc degeneration. For L5-S1 disc degeneration, only the presence of transitional vertebra was signicantly related. When there is no transitional vertebra, the probability of disc degeneration is 9 times(8.889) as large as that of presence of transitional vertebra. The probability of L4-5 disc degeneration without the degeneration of L5-S1 is 3 times as large as that of degeneration of both of L4-5 and L5-S1 disc in case of the presence of transitional vertebra.