Objective:To study the total serum IgE level of infant's asthmatic diseases in acute attacks and its effect on the development of wheezing.Method:The serum IgE levels of 964 children(younger than two years old)diag- nosed as asthmatic bronchitis or bronehiolitis were measured by immune dispersion nephelometer.Result:78.9% childrens had high E levels(females took up 25.9% and males,74.1%),asthmatic bronchitis accounted for 92.3% of the total and bronehiolitis,60.3%.Of the 328 infants involved in our research,76 were diagnosed as asthma at last,which accoun- ted for 23.2%.Conclusion:78.9% infants had a high level of IgE in an acute phase.There was a prominent relativity be- tween IgE and the development of asthma.The increased IgE level of asthmatic bronchitis was obviously higher than that of the bronchiolitis.There appeared to be a connection between the IgE level and the occurrence of asthmatic bronchitis to- gether with the development of asthma.