Objective: This epidemiology survey is intended to assess the periodontal health conditions of 12 to 15-year-old adolescents and the associated factors in Shenzhen. Methods: The study utilized a multistage stratified cluster method and recruited 5 509 middle school students aged 12 to 15. Gingival bleeding and calculus were conducted and a self-reported questionnaire was administered. Additional periodontal pocket depth and attachment loss examination were performed in the 15-year-age group. Periodontal conditions and the associated factors were analyzed by t-test, Chi-square method and Logistic regression. Results: The prevalence of gingival bleeding and calculus among adolescents was 43.95% and 44.25%, and the prevalence of periodontal pockets ≤3 mm was 0.57%. No periodontal pockets ≥6 mm or attachment loss ≥4 mm were detected. Gender, family income and frequency of teeth brushing were significantly associated with calculus detection (P＜0.05). The use of fluoride had an significant effect on gingival bleeding detection and calculus detection (χ 2=9.70，6.16，P＜0.05). Conclusion The periodontal health condition among 12-15 years old adolescents in Shenzhen is generally better than the national level. Adolescents living in high-economic districts and females had better periodontal health condition. The government can promote health education in schools and popularize the use of fluoride to improve the periodontal health condition among adolescents.