【Abstract】 Objective To discuss the main points of techniques and ranges of fusion in posterior operation ofdegenerated lumbar scol iosis compl icated spinal stenosis. Methods From February 2001 to September 2006, 23 cases with degenerated lumbar scol iosis stenosis were treated by posterior operation. There were 9 males and 14 females, with the average age of 65.3 years (ranging from 52 years to 71 years). The course of the diseases was 4 to 8 years. All patients were presented with severe low back pain. All patients were measured for Cobb angle of curves(17° to 53°), and lordosis angle of lumbar (-20° to -10° 10 cases, -40° to -20° 13 cases). Ten cases in which Cobb angle was smaller than 20° were operated by l imited segmental decompression of spinal canal, posterior intervertebral fusion and short transpedical instrument fixation. For the rest 13 cases in which Cobb angle was bigger than 20° were operated by canal decompression, longer instrument for scol iosis correction, intervertebral fusion and posterior-lateral fusion. The fixation and fusion were located at L4-S1 in 6 cases, L1-5 in 5, L2-5 in 4, L1-S1 in 5, L2-S1 in 2 and T10-S1 in 1. Results There was no patient who died from the operation. Average Cobb angle in coronal plane was 0° to 21° with the average of 15.6°. The lumbar lordosis angle was -48.0° to -18.2° with the average of -36.4°. There were 21 cases (91%) with sciatica and intermittent claudication who were clearly released. There were 20 cases (87%) whose low back pain intensely decreased. Three cases with drop-foot returned to normal activities. During the mean 15-month (6 to 54 months) follow-up for 23 cases, there was no change of corrected results and fusion rate was 100%. Conclusion For degenerated lumbar scol iosis patients, the most important purpose of the treatment is to improve cl inical symptoms through sufficient decompression of neural structures. Lumbar stabil ization reconstruction and benign spinal biomechanics l ine conduce to longterm curative effect. Overall estimate of the cl inical appearances and imageology characters is necessary when the decision, that segments are needed to be fixed and fused should be made. The strategy of the individual ized treatment may be the best choice.