Objective To establish a mice model of atopic dermatitis with acute itching and investigate the antipruritic effect and its mechanism of Xiaofeng Zhiyang granules(XFZYG).Methods A mice model of atopic dermatitis was prepared by induction method.Mice were sensitized by calcipotriol and ovalbumin(OVA)applying to the right ear daily for 10 days,and then stimulated by OVA injected intradermally into the right cheek to resulting in acute itching.These mice were divided into 5 groups:blank control group,model group,low dose(7.2 g/kg)and high dose(14.4 g/kg)of XFZYG,and positive control group(montelukast 5 mg/kg).Drugs were administered by gavage at 12 h and 30 min before stimulation.The leukotriene levels in the serum of the mice were measured by Elisa and the basophil ratio and activation status in the blood were measured by flow cytometry.Results The mean number of scratches in the model group was 56 between 30 min and 60 min after stimulation,while the mean number of scratches in the low and high dose of XFZYG groups were 42 and 23 respectively,which were significantly lower than those in the model group(P<0.05).The serum leukotriene levels and the proportion of basophils in the low and high dose of XFZYG groups were significantly lower than those in the model group(P<0.05).Conclusion XFZYG had certain therapeutic effect on acute itching of atopic dermatitis in mice,and the mechanism of its action was related to the reduction of leukotriene level and basophil ratio in serum of mice with atopic dermatitis.