Objective   To explore knowledge and belief related to smoking and health and their association with smoking behaviors among secondary school students.

  Methods   Self-administrated questionnaire was applied to the first, second and third year secondary school students in Huangpu district of Guangzhou.

  Results   Of the investigated 8 656 students, the mean score of knowledge about diseases caused by smoking(maximum=10)and harmful components in cigarette(maximum=4) was 4.87 and 2.13, respectively.Mean scores of belief related to smoking and health were: 25.88 for effect of smoking (maximum=30), 21.33 for identification with appearance of smoking(maximum=25), 32.07 for identification with sociality effect of smoking(maximum=40)and 32.69 for agreement with measures of preventing and controlling smoking(maximum=40).Ratios for the mean score vs the maximum were 0.86, 0.85, 0.80 and 0.82, respectively.Prevalence of trying smoker, irregular smoker and regular smoker was 16.6%(25.6% for male and 6.3% for female), 12.0%(18.0% for male and 5.1% for female)and 4.7%(7.6% for male and 1.1% for female).In males, the mean score of the knowledge and the belief in regular smokers was the highest, followed by irregular smokers and non-smokers, and the difference was significant in statistics.In females, the mean score of the knowledge was not significant among regular smokers, irregular smokcers and no-smokers, while a signigcant statistics difference was obtained for the mean score of the belief among regular smokers, irregular smokers and no-smokers.

  Conclusion   Contrast to the higher score for the belief related to smoking and health, the knowledge related to smoking and health was the lower among the surveyed secondary school students.The knowledge and belief relevant to smoking was associated with different smoking behaviors among the secondary school students.