Objective To compare the effectiveness of two oral health education program among middle - school students on improving oral health status. Methods Three middle schools randomly chosen from the urban district of Deyang city were divided into three groups: teacher- based group （Group T）, parents- based group （Group P）, and the control group（Group C）. Oral health education sessions were conducted for teachers（Group T） and parents （Group P）of these children. Students obtained oral health knowledge through their teachers（Group T）or their parents （Group P）, brushed their teeth twice daily. No oral health education session was carried out in the control group. The effectiveness of oral health status in three groups were compared after 3 months. Results The debris index （DI）, calculus index（CI） and gingival index（GI） of group T obviously decreased after 3 months（P
