OBJECTIVE To investigate the effects of Huobahuagen tablet on the expression of interleukin-3 (IL-3) receptor mRNA in bronchoalveolar lavage fluid (BALF) and infiltration of eosinophil (Eos) in the airway of asthmatic guinea pigs. METHODS Thirty-two healthy guinea pigs were randomized into 4 equal groups, the control group, asthmatic group, dexamethasone therapy group and Huobahuagen tablet therapy group. Asthma was induced in the latter 3 groups which were challenged with the asthma-inducing agents and at the same time received treatments as indicated. BALF were collected subsequently from the guinea pigs for examining the total cell number and cell classification, and histopathologic examination of the lung tissue was performed. Semi-quantitative analysis with reverse transcriptional-polymerase chain reaction (RT-PCR) of IL-3 receptor mRNA in the BALF was performed. RESULTS Compared with the control and the asthmatic group, the number of Eos in the BALF of Huobahuagen tablet therapy group was significantly lower (P<0.05 and P<0.01, respectively). In spite of the presence of hyperemia and edema in the lung tissues of the Huobahuagen tablet therapy group, Eos infiltration was less severe than that in the asthmatic group. As found by RT-PCR, the quantity of IL-3 receptor mRNA in the BALF of the Huobahuagen tablet therapy group did not significantly differ from that in the dexamethasone therapy group, but was significantly higher than that in both the control and asthmatic group (P<0.01). CONCLUSION Huobahuagen tablet can significantly lower the number of Eos in the airway of asthmatic guinea pigs, a finding that may potentially serve as the elementary theoretical basis for clinical therapy of asthma.