CT of 10 calcified herniated lumber discs among 46 operated cases were analysed at the aspects of incidence, location, shape, etc. The results are as follows: 1. The incidence of calcification is 22%(10/46). 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 herniation (8 cases) are more common than posterolateral herniation(2 cases). 4. Linear or band-like calcifications in the periphery of herniated disc (annulus fibrosus type) are 6 cases and dense patchycalcification in the central portion of herniated disc (nucleus pulposus type ) are 4 cases. 5. Two cases (50%) of 4 cases with nucleus pulposus type calcification were found to be ruptured at operation, but none of 6 annulus fibrosus calcification types showed 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 preesence, location, andtype of calcification in herniated disc in detail.