Abstract: In the global scope，the morbidity and mortality of bronchial asthma in children is increasing. The main causes include both the genetic factors and the environmental factors，especially the interaction between them. Epigenetics brings about the gene mutation through the environmental factors，which can be passed on to the next generation. It is an important factor of the higher incidence of bronchial asthma in children. Epigenetic modification not only affects the prevalence of asthma but may also affect the control level of asthma. Understanding the characteristics of interaction between genetic factors and environmental factors，especially the epigenetic characteristics，can provide new ideas for the early diagnosis and early intervention of childhood bronchial asthma.

Key words: Asthma, Genes and environment, Epigenetics, Children