Abstract: An investigation of children’s passive cigarette smoking in 8 elementary schools in Lanzhou,Chongqing,Wuhan and Guangzhou from 1993 to 1996 has been reported by this paper.Among those 7977 children who were between 7 and 12 years old,6342 children,namely 79 5%,were exposed to passive smoking caused by family members.Prevalence of ten kinds of respiratory system illness or symptom is significantly higher among those who exposed to passive cigarette smoking than among thsoe who never.Odds ration (OR) of 8 illness or symptom is within 1 27～1 67, and to hospitalization,the number is 1 28. Moreover,the more family member smoke, the higher the prevalence of children’s illness or symptom,and OR as well.