IN A SERIES of 63 patients with degenerative spondylolisthesis, methods of surgical treatment were analyzed. Patients were divided into two groups according to surgical treatment. Two kinds of treatment: decompression only (14 patients) & decompression with instrumented (49 patients). We evaluated the surgical method of treatment, clinical and radiological outcome in the two groups. We found that fusion group has nonsignificant better outcome in improvement rate (P>0.05) than decompression only group and significantly more hospital stay (P< 0.05). And that decompression only group had significant more decrease in angle of lordosis than fusion group (P< 0.05).