Objective: To understand the prevalence and related factors of tobacco use among junior high school students in Beijing, so as to provide evidence to effectively conduct tobacco control intervention strategy. Methods: From April to June in 2019 and 2023, 6 489 and 6 898 junior high school students were selected by the probability proportion to size(PPS) method, and a total of 13 387 questionnaires were completed. Questionnaire on tobacco monitoring among junior high school students in Beijing was completed by selffilling. The monitoring content included demographic information, secondhand smoke exposure, tobacco product use, tobacco awareness, etc. Chisquare test was used to compare the difference of various indicators in different groups, and multivariate Logistic regression analysis was adopted to analysis the influencing factors related to the current smoking among junior high school students. Results: In 2019,the current traditional cigarettes and ecigarette smoking rates among junior high school students in Beijing were 1.34%, 1.88%, respectively, and decreased to 0.81%, 1.06% in 2023 (χ2=8.36, 15.17, P＜0.01). The attempted traditional cigarettes and ecigarette smoking rates among junior high school students in Beijing decreased from 6.67%, 6.47% in 2019 to 3.93%, 4.16% in 2023 (χ2=49.99, 35.26, P＜0.01). In 2019, the secondhand smoke exposure rates of junior high school students at homes, indoor public places, and outdoor public places were 31.04%, 44.94%, and 49.88% respectively which decreased to 22.59%, 30.23%, and 36.14% in 2023 (χ2=121.63, 308.60, 257.41, P<0.01). In 2023, male students (OR=2.88), senior students (grade 2 and 3) (OR=4.37, 4.92), disposable pocket money>20 yuan/week (OR=2.01), secondhand smoke exposure at home (OR=2.74), indoor public places (OR=2.64), perception that smoking makes young people more attractive (OR=6.29), and perception that ecigarettes help quit smoking (OR=4.31) were associated with higher tobacco use (P<0.05). Conclusions Tobacco use and secondhand smoke among junior high school students in Beijing decrease significantly. Tobacco control interventions should be provided for junior high school students continuously with a focus on ecigarettes use to promote physical and mental health development among students.