Objective To investigate the risk factors of childhood asthma in Haikou city. Methods Cluster sampling survey method was used to select 13 kindergartens and community health care institutions in Haikou city from January to December in 2016.Totally 7 256 children aged 3~6 were surveyed and Logistic regression analysis was used to analyze risk factors. Results The positive rate of asthma index was 6.74%in preschool children of Haikou city.Factors affecting the incidence of asthma were complicated,of which the...