Rationale Matrix metalloproteinase-9 (MMP-9) is one of the major proteolytic enzyme that induces airway remodeling in asthma. MMP-9 also induce inflammatory cell accumulation, extracellular matrix deposition, airway smooth muscle hyperplasia/hypertrophy and airway fibrosis. We studied first the production of MMP-9 in obalbumin (OVA)-induced asthma model mice and in A549 cells treated with phorbol 12-myristate 13-acetate, and examined the effect of protein kinase C (PKC) inhibitors, calphostin C and chelerythrine chloride on MMP-9 expression in murine model of asthma and in A549 cell line. Methods Expression and activity of MMP-9 was identified by gelatin zymography, western blotting, reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Results We observed significant decreases in the accumulation of inflammatory cells and the expression of MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in administration of PKC inhibitor, calphostin C and chelerythrine chloride. Conclusions In this study, we suggest that PKC inhibitors inhibit accumulation of inflammatory cell through down -regulation of MMP-9.