Objective ： Lonicera japonica contains anti complementary polysaccharides and polyphenolic compound. Among these polyphenolic substances, chlorogenic acid is the major active component of this plant. However, the immunological mechanisms for these activities, have not been elucidated, nor the active components. To clarify immunomodulatory effects of those we examined the relationship between the activity of CD8+ T cell-mediated lysis and the frequency of cytokine profiles in spleen, thymus (especially IFN-${gamma}$, IL-4, GM-CSF etc.) expressing CD8+ T cells activated by IL-2. Methods : To study immunomodulatory effects ethyl acetate fraction from Lonicera japonica, chlorogenic acid on cytokine gene expression from spleen, thymus cells, RT-PCR was performed after quantitative normalization for each gene by a densitometry using ${eta}$-actin gene expression. A modified standard $^{51}Cr$-release assay was used to measure cytotoxic activities of cytotoxic T cells. Spleen, thymus cells from NOD mice were stained with CD3, CD4, CD44, CD69 in staining buffer and analyzed by two color flow cytometry. Results : We showed that ethyl acetate fraction from Lonicera japonica in combination with IL-2 resulted in a significant enhancement of PCR products for IFN-${gamma}$, IL-4, IL-10, GM-CSF, IL-6 and cytotoxtic CD8+ T cell proportion in spleen and thymus T cells in NOD mice. This suggests that IFN-${gamma}$, IL-6 like IL-4 may be acting as a regulatory rather than proinflammatory cytokine. Conclusions : In conclusion, based on the results of the present study which showed that ethyl acetate fraction from Lonicera japonica and chlorogenic acid upregulating cytokine gene expression in spleen and thymus, we are tempted to speculate that some of the therapeutic efficacies such as anti-diabetic activity of Lonicera japonica are due to the immunomodulatory its ethylacetate fraction and chlorogenic acid.