From 1973 to 86, 308 patients were operated upon for protruded lumbar vertebral disc. 17 of them had 22 discs protruded and 19 of the 22 discs had been ossified. Operative findings and pathological characteristics of the specimens suggested that the ossified mass could be the result of ossification of the superficial tissue of the protruded disc, a sequence of turnover of fibrocartilage into osseous matter. We are of the confidence that operation is the choice of treatment of such lesion; and it should be performed early following diagnosis, as the ossified mass could never be absorbed, but progress on. The symptoms, lumbago and sciatica, of the 17 patients went immediately off after operation. Follow-up of 16 of them for 1.5 to 7.5 years (averaging 2.5 yrs.) showed excellent and good results in 87.8%.