Backgrounds & Objectives: In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of asthma. Recently, as a method of research on the gene expression, they are applying another method which assays multiple gene expressions at the same time by the microarray. In this study, the antioxidant effect, the inhibitory effect against interleukin-4 and the effect on the CD/cytokine gene expression in PBMC (peripheral blood mononuclear cells) was evaluated by using cDNA microarray chip of Chungsangboha-tang. Methods: Experimental studies were performed for the antioxidant effect of Chungsangboha-tang on DPPH (1, 1-diphenyl-2-picrylhydrazyl) solution, for the IL-4-inhibiting effect on BALB/c mouse spleen, and for the gene expression effect on PBMC (peripheral blood mononuclear cells) with microarray. Results: Chungsangboha-tang showed antioxidant effect dose-dependently. Chungsangboha-tang inhibited interleukin-4 dose-dependently and showed significant difference in 10ug/ml and 100ug/ml of test groups. There was no 2 more times upregulated genes than in the control group by using cDNA microarray chip of Chungsangbohn-tang, but there were 140%-200% upregulated genes. There was no 2 more times downregulated genes than in the control group by using cDNA microarray chip of Chungsangboha-Tang, but there was 50%-75% downregulated genes. Conclusions: This study showed that Chungsangboha-tang has an antioxidant effect and inhibition of Interleukin-4, but further studies are necessary with microarray.