The effects of cereal (rice, brown rice, barley, glutinous rice) ethanol extracts on the proliferation, nitric oxide (NO) production, and level of tumor necrosis factor-${alpha}$ (TNF-${alpha}$) in B and T lymphocytes, isolated from human blood cells of sasang constitution, were examined in vitro. The rice, brown rice, and glutinous rice ethanol extract, which are known as suitable for eumin (taeumin and soeumin) constitutions, showed the highest activities for proliferation, NO production, and TNF-${alpha}$ concentration, respectively. However, the barley ethanol extract, which is known tobe suitable for yangin (taeyangin and soyangin) constitutions, showed the highest overall activities for proliferation, NO production, and TNF-${alpha}$ concentration. The different immunological activities of the cereal extracts in sasang constitution lymphocytes might be due to their individual components. Thus, determination of components from the cereal extracts suitable for sasang constitution could be useful in new food developments.