Objective To investigate the inhibitory effect of matrine on inflammation by regulating Th1/Th2 bal-ance in asthmatic rats and the underlying mechanism related to SOCS3.Methods Ovalbumin-sensitized rats were established as asthma model, Animals randomly divided into four groups, as follows: control ( without any treatment) , model group, treatment group A ( low-dose matrine treated asthma rats ) and treatment group B ( high-dose matrine treated asthma rats) .The eosinophil counting, goblet cells percentage, inflammatory cell in-filtration in rat lung were analyzed and scored by morphological examination .IL-4 and IFN-γlevel in BALF were determined by ELISA and IFN-γ/IL-4 ratio was further calculated.Furthermore, the expression of SOCS3 in mRNA and protein level were detected by qRT-PCR and Western blot, respectively.Results Eosinophil count and percentage, goblet cell percentage and inflammatory cell infiltration score were significantly lower than that in treatment group A and B as compare to model group ( P<0.05 ) .The group A exhibited a lower IFN-γlevel and a higher IL-4 level ( P<0.05 ) .IFN-γlevel in treatment group A and B were higher while IL-4 level were lower as compare to model group.Meanwhile, SOCS3 mRNA level in rat lung tissue was elevated in model group.Ma-trine treatment decreased SOCS3 expression in group A and B .Similar trend was found in SOCS3 protein level. Conclusions Matrine may exhibit antiinflammatory effect by inhibiting SOCS3 expression and correcting Th1/Th2 balance in asthmatic rats.