Objective　To observe the effects of the periodontal subgingival scaling in different stages of standardized residency training of stomatology general medicine. Methods　Thirty residents in Affiliated Stomatology Hospital of Zhejiang University School of Medicine were recruited by stratified randomization and divided into three groups

including 1-month group

3-month group and 6-month group. The residual ratio of clinical calculus was compared after periodontal subgingival scaling among groups. SPSS 23.0 was conducted for Kruskal-Wallis H test. Results　The mean residual ratio of clinical calculus in 3-month group and 6-month group were significantly lower than that in the 1-month group. In the 3-month group

the scaling could only achieve the effective results at the shallow pockets and anterior tooth area. Compared with the 1-month group

the 6-month group significantly decreased the residual ratio of clinical calculus for the sites with pocket depth of 4-6 mm

but there were still insufficiency to deal with the posterior tooth area. Conclusion　The 3-6 months residency training of periodontology could improve the effectiveness of the periodontal subgingival scaling. We should establish reasonable assessment and evaluation system according to different stages of residents

and the subgingival scaling training in the posterior areas and the distal interproximal sites should be reinforced in order to more effectively improve the quality of the standardized residency training.