Objective:To evaluate curative effect of minocycline collagen sponge preparated by us in the treatment of chronic peridentitis after local application.Methods:The minocycline was preparated by freeze drying method.A total of 100 teeth were selected in 25 patients with chronic peridentitis and control group.There were 50 teeth in each group.Probing depth was longer than 5 mm and target site was tooth site of the bleeding on probing.All the patients received scaling before baseline and the clinical parameters including plaque index (PLI),probing depth (PD),attachment loss(AL),and bleeding on probing (BOP) at baseline were examined and recorded.Subgingiral scaling was performed in the control group.Minocycline collagen sponge was put in periodontal pocket after subgingival scaling in the treatent gropu,one time weekly for four weeks.Above clinical parameter were examined at 4 th ,8 th ,10 th wk respectively.Results:There was significant improvement in the clinical parameters.A degree of improvement in the treatment group was more significant than that in the control group and the difference between two groups was significant.Conclusion:Local application of minocycline collagen sponge in the periodontal pocket,used as adjuvant for routine scaling can effectively eliminate inflammation in the periodontal tissue from destruction. Objective: To evaluate curative effect of minocycline collagen sponge preparated by us in the treatment of chronic peridentitis after local application. Methods: The minocycline was preparated by freeze drying method. A total of 100 teeth were selected in 25 patients with chronic peridentitis and control group . Every 50 teeth in each group. Probbing depth was longer than 5 mm and target site was tooth site of the bleeding on probing. All the patients received scaling before baseline and the clinical parameters including plaque index (PLI), probing depth (PD ), attachment loss (AL), and bleeding on probing (BOP) at baseline were examined and recorded. Subgingiral scaling was performed in the control group. Minocycline collagen sponge was put in periodontal pocket after subgingival scaling in the treasury gropu, one time weekly for four weeks. Abdominal clinical parameters were examined at 4 th, 8 th, 10 th wk respectively. Results: There was significant improvement in the clinical parameters. A degree of improvement in the treatment group was more significant than that in the control group and the difference between two groups was significant. Confc: Local application of minocycline collagen sponge in the periodontal pocket, used as adjuvant for routine scaling can effectively eliminate inflammation in the periodontal tissue from destruction.