Bio-Q is a modified prescription with the activities of supplementing Qi and blood in human body. In the present study, immunomodulatory effect of Bio-Q was examined. After oral administration of Bio-Q for 7 days to Balb/c mice, splenocytes were isolated and immunological experiments were performed. Bio-Q significantly increased the proliferation of splenocytes exposed to concanavalin A (Con A), while it did not in case of lipopolysaccharide (LPS) stimulation. Bio-Q also significantly increased CD3/CD19, CD4/CDB and NK cells by flow cytometric analysis. In addition, Bio-Q significantly enhanced the level of $INF-gamma$ in splenocytes, but not $TNF-alpha$ by ELISA. These results strongly suggest that Bio-Q has immunomodulatory activity through the regulation of T cell mediated immune pathway.