Study Design This is a retrospective study. Purpose We wanted to measure the distance of the normal intervetebral disc space of Koreans. Overview of the Literature For judging the distance of the normal intervertebral disc space of Koreans, we studied young adults who didn't have degenerative spinal change to determine the distance of the normal intervertebral disc space of each lumbar vertebral segment, and we did so by performing magnetic resonance imaging (MRI). Methods We studied a total of 178 outpatients who had low back pain and they underwent lumbar MRI. There were 138 males and 40 females, and their average age was 20.7 years (range, 15 to 25 years). On MRI, the segments with observed Modic change or other abnormalities were excluded from this investigation. To improvement the accuracy of measurement, two spine specialists measured the distances 2 times, and we calculated the mean value. We used paired t-tests for statistical analysis. Results In the total 178 patients, the average distance of intervertebral space from the 1st to the 2nd lumbar vertebrae was 24.83% (range, 18 to 32%), that from the 2nd to the 3rd was 26.92% (range, 19 to 40%), that from the 3rd to 4th was 28.88% (range, 19 to 41%), that from the 4th to 5th was 29.60% (range, 21 to 43%) and that from the 5th lumbar vertebra to the 1st sacrum was 27.52% (range, 19 to 38%). Conclusions In this study, we expect that knowing the normal distance of the lumbar intervertebral space of Koreans can be helpful for surgical reconstruction to treat many lumbar spine diseases, to predict the appropriate size of the devices inserted in the intervertebral space and to produce proper devices for Koreans.