Osteochondroma is the most common benign tumor of bone, of which the typical form is a cartilagecapped bony projection, far often found at the metaphysis of the long tubular bones, and may arise from any bone performed in cartilage. To our knowledge, however, osteochondroma of lumbar spine has been reported 11 cases, but We experienced a case of osteochondroma located in the position normally occupied by right side lamina of 5th lumbar vertebra. The mass was excised and disclosed typical microscopic findings of osteochondroma.