OBJECTIVE： To investigate the clinical efficacy of Bacterial lysates capsule in the treatment of acute attack of asthma in children， and its effects on inflammatory factors and respiratory mechanics indexes. METHODS： A total of 87 children with acute attack of asthma in our hospital were divided into observation group （44 cases） and control group （43 cases）. Control group was given glucocorticoid Beclomethasone dipropionate aerosol 0.05 mg， tid； observation group was additionally given Bacterial lysates capsule 3.5 mg， qd， on the basis of control group. Both groups received 120 days of treatment. Peripheral Th1/Th2 cell factor levels （IFN-γ， IL-2， IL-4， IL-5， IL-10， IL-13）， lung function indexes （FVC， FEV1， PEF）， respiratory mechanics indexes （mean airway pressure， respiratory resistance， static compliance， measured plateau pressure） and clinical efficacies were observed in 2 groups. RESULTS： Before treatment， there was no statistical significance in Th1/Th2 cell factors， lung function indexes or respiratory mechanics indexes between 2 groups （P＞0.05）； after treatment， the levels of IFN-γ， IL-2， IL-10， FVC， FEV1 and PEF were increased significantly， while the levels of IL-5 and IL-3 were decreased significantly； IL-4 level of control group was decreased significantly； the levels of IL-2， IL-4， IL-10， FVC， FEV1 and PEF in observation group were significantly better than control group， with statistical significance （P＜0.05）. Mean airway pressure， respiratory resistance and measured plateau pressure of observation group were significantly lower than those of control group， while static compliance was significantly higher than control group， with statistical significance （P＜0.05）. Response rate of clinical control in observation group was 77.27％， which was significantly higher than 55.81％ of control group， with statistical significance （P＜0.05）. CONCLUSIONS： Bacterial lysates capsule shows significantly therapeutic efficacy for acute attack of asthma， relieves airway inflammation and improves the immunity level of the body so as to improve airway respiratory mechanics parameters.