Abstract: ObjectiveTo explore the prevalence of household passive smoking and its risk factors among children in Macau Special Administrative Region of People's Republic of China(Macau)and to provide evidences for making measures for preventing the children from secondhand smoke.MethodsConvenient sampling method was adopted to select 875 parents of children aged 6 to 14 years in first,third or fifth grade of 4 elementary schools and a questionnaire survey was conducted among the participants.Logistic regression analysis was applied to determine the risk factors of household passive smoking.ResultsThe 875 participants reported an overall prevalence rate of 37.0% of household passive smoking among their children and 28.3% of the children exposed to the secondhand smoke(SHS)at home every day.There was no significant difference in the passive smoking prevalence between the boys and girls(χ²=0.326,P>0.05).Among the parents surveyed,the prevalence rate of current smoking in the fathers was 43.7%,much higher than that in the mothers(3.8%)and in the grandparents(8.3%).Father's smoking was the most important risk factor of SHS exposure at home among the children(odds ratioOR=34.061,95% confidence interval95% CI:21.819 -53.173)and the smoking status of a father was influenced by education level of the father(OR=0.606,95% CI:0.513-0.716)and the age of the mother(OR=0.973,95% CI:0.950-0.997).Single mothers were more likely to be smokers than the mothers of two-parent family(OR=8.137,95% CI=3.209-20.637).ConclusionThe prevalence of household passive smoking is relatively high and influenced mainly by parental smoking among the children in Macau,suggesting the control of parental smoking could decrease SHS exposure at home effectively among the children.