This study was aimed at investigating hepatic toxicity and immunomodulating effects of defatted methanol extracts of two kinds of medicinal plants, Rubus coreanus Miq. and Atractylodes japonica Koidz. in mice. Defatted methanol extracts of fruits of Rubus coreanus Miq. and rhizome of Atractylodes japonica Koidz. were added at the level of 0.5% or 5%(w/w) to cholesterol-supplemented AIN-76 diet. Each diet was fed to 8 ICR male mice for 30 days. Weight gain and food efficiency ratio of the mice fed 5.0% extract of Rubus coreanus Miq. were significantly lower than those of the mice fed 0.5% extract Relative liver weight and activity of plasma alanine aminotransfernse were significantly increased only in the mice fed 5% extract of Atractylodes japonica Koidz. compared with the others. Splenocyte proliferation was not significantly different between the groups fed 0.5% or 5.0% extract of Rubus coreanus Miq. However, splenocyte proliferation was significantly decreased in the mice fed 5.0% extract of Atractylodes japonica Koidz. compared with that in the mice fed 0.5% Production of interleukin-2 by splenocytes from the mice fed 0.5% extract of Atractylodes japonica Miq. was significantly higher than the control value and it became lower with 5.0% dietary level. Secretion of $interferon-gamma$ was not significantly different among groups. In conclusion, the defatted methanol extract of Atractylodes japonica Koidz. was likely to exert immunomodulating effect at the level of 0.5% but it may exert adverse effects on immune and liver functions at the level of 5.0%.