CT of 10 calcified herniated lumber discs among 46 operated cases were analysed at the aspects of incidence, location, shape, etc. RESULTS : 1. The incidence of calcificaton is 22%. 2. Among 10 cases, 3 cases are at the level of L4-5 disc space and 7 cases are at the level of L5-S1 disc space. 3. Central harniation are more common than posterolateral herniation. 4. Linear or band-like calcifications in the periphery of herniated disc are 6 cases and dense patchy calcification in the central portion of herniated disc are 4 cases. 5. Two cases of 4 cases with nucleus pulposus type calcification were found to be rupture. 6. Because more wide operation field and invasive exploration were required in calcified cases than non-calcified cases, it is suggested to evaluate the presence, location, and type of calcification in herniated disc in detail.