Abstract： Objective To screen the relative risk and protective factors of children patients with asthma after capillary bronchiolitis.Methods The clinical and follow-up data of 220 children patients with capillary bronchiolitis were collected.Sex,treatment method,immunization vaccination,idiosyncrasy,feeding way,family history were investigated and analyzed.The risk factrs of asthma were screened.Results Univariate analysis showed that the incidence of asthma between different genders had no significant difference (P ＞0.05).The asthma incidence in patients with BCG vaccination on time and large-dose immunoglobulin treatment were lower than those in patients without BCG vaccination on time and large-dose immunoglobulin treatnent (P＜ 0.01 ).The asthma incidence in patients with idiosyncrasy,family history was significantly higher than that in patients without idiosyncrasy,family history( P ＜ 0.05 ).The asthma incidence in patients with obesity was higher than that in other children (P ＜ 0.05).The asthma incidence in patients with more than 4 months breast feeding was lower than that in patients with other feeding ways (P ＜ 0.05 ).Multi-factors regression analysis showed that family history,obesity,idiosyncrasy were the risk factors of asthua,and large-dose immunoglobulin treatment,BCG vaccination on time,breast feeding ＞ 4 months were the protective factors.Conclusions Family history,idiosyncrasy,obesity are the risk factors of asthma in children patients with capillary bronchiolitis,and should be focused on olservation.Immunoglobulin treatment and procedural BCG vaccination are the protective factors to reduce the asthma incidence.They are worthy of application especially in children with risk factors.