Objective:To study the relationship between Modic changes and the degree of disc degeneration in patients with degenerative spondylolisthesis before surgery. Methods:From January 2009 to December 2011,44 cases of patients who had the degenerative spondylolisthesis were treated by operation. Preoperative MRI was performed to classify the Modic changes type. Pfirrmann grading assessment and modified Pfirrmann grading assessment were also perfomed. Then,the relationship between Modic changes and the degree of disc degeneration were analyzed in these patients with degenerative spondylolisthesis. Results:Among 44 cases,12 cases had no Modic changes,Pfirrmann grades were 3.92 ± 0.29,modified Pfirrmann grades were of 5.92 ± 0.90;16 cases were ModicⅠ type,Pfirrmann grades were 4.31 ± 0.60,modified Pfirrmann grades were 6.88 ± 1.54;15 cases were Modic type Ⅱ,Pfirrmann grades were 4.27 ± 0.46,modified Pfirrmann grades were 6.87 ± 0.83;Only 1 case of Modic type Ⅲ was found. Statistic analysis showed that modified Pfirrmann grades were significantly different between ModicⅠtype group and no change group(P < 0.01);Differences were also exsit between Modic Ⅱ type group and no change group(P < 0.01);But,there was no significant difference between ModicⅠtype group and Modic Ⅱ type group(P > 0.05). Conclusion:In degenerative spondylolisthesis,there is a clear connection between the Modic changes and the degree of disc degeneration according to the Pfirrmann and modified Pfirrmann grading system assesment.