Spinal stenosis is defined as any type of narrowing of the main spinal canal, nerve canal or foramina. It's pressure symptoms are characterized by ill localized back pain, and usually bilateral claudication. The diagnosis and treatment of spinal stenosis have been facilitated due to introduction of myelo enhanced computerized tomography and magnetic resonance imaging. During the period of 4 years, from March 1986 to March 1990, we experienced 55 cases of spinal stenosis at In-Ha Hospial. But this study was confined to evaluate the 25 of our 55 cases, which were diagnosed cases as degenerative type and carried out surgery. 1. The peak incidence of age ranged from 50 to 69 years, which comprised 15 cases(60.0%). 2. There were 11 males and 14 females. 3. The most common chief complaints on admission were pain in low back and claudication. 4. The Myelo Enhanced Computerized Tomography(MECT) was performed in 25 cases and the most common MECT finding was narrowing of central portion of spinal canal and lateral recess. The most common lesion site was in the 4th lumbar vertebra. 5. The MECT results of all patients with claudication were less than 10mm of AP dia. and llmm of interfacetal dia. of spinal canal. 6. Decompressive surgery was carried out on 25 patients as in the following one level 13, two levels 9, and more than three levels 3. Posterolateral fusion was carried out 17 cases(68.0%). 7. The longest follow-up was 3 years and the shortest one was 1 year. The average is one year and ten months. The results were as follow : excellant 48.0%, good 36.0%, fair 12.0%, poor 4.0%.