Abstract: The purpose of this study was to evaluate the situation of the bacterial growth in patients with periodontal diseases by means of microscopy.Comparision was made between the periodontal involoved teeth atad inflammation-free teeth. Microbial samples were collected from the periodontal pockets and gingival sulci.The effects of subgingival curettage and Chinese herb medicine were also evaluated. Correlations between PH value of cervical fluid and number of bacterial growth were determind. The following assessments were recorded,motile rods and Gram negative rods increased with increase in severity of the periodontal disease,and cocci increased with the resolution of the imflammation.Curettage would cause a decrease of Gram negative rods and an increase of cocci, Chinese herb medicine caused a diminution of spirochetes and motile rods.Numbers of bacteria increased as the PH value of gingival fluid decreased.