This study was designed to elucidate the effects of mugwort powder supplemented to high fat diets on blood components levels in rats. The levels of mugwort content in the experimental diets were divided into 12, 21, 28% and the fat levels in high fat diet was 30% of total caloie intake. Forty-nine male Sprague-Dawley rats weighing 72.5$pm$0.3g were divided into group I(add mugwort during 8 weeks), group II(add during 4 weeks) andcontrol group. The results of this study were summarized as follows : 1. There were no difference in body weight gain and FER throughout eight weeks of experiment. The organ weights were somewhat higher in control group, but not significant. 2. The mugwort groups(I, II) were significantly higher than control group in RBC. This result showed that the mugwort affect the content of RBC. Author would like to conclude this result that the RBC content of experim-ental animal was affected by the iron in the mugwort. There were no difference among experimental groups in Hb, Hct. 3. It was noteworty that the concentration of serum glucose and triglyceride in the mugwort groups(I, II) was significantly lower than the control group. This result concluded that concentration of serum glucose and triglyceride which had become high by high fat diet were affected by the calcium or dietary fiber in the mugwort. There were no difference among experimental groups in albumin, total cho-lesterol, HDL-cholesterol.