This study was designed to know the effect of kimchi on the hematological and immunological parameters in vivo and in vitro, respectively. To study the effects of kimchi on the hematological parameters, rats(S.D., male) were divided into 4 groups and fed diets containing of 3%, 5% and 10% kimchi or kimchi free diet(control) for 6 weeks. The results of CBC(complete blood cell) tests obtained from the bloods of rates were as follows ; In 10% kimchi group, the level of WBC(white blood cells), RBC(red blood cells), Hgb(hemoglobin), Hct(hematocrit) were increased significantly than those of control group(p<0.05). MCV(mean corpuscular volume), one of the red cell indices, was also increased significantly in the animals fed 10% kimchi(p<0.05). RDW(Red cell distritution width) and PCT(plateletcrit) was lowest in 10% kimchi group(p<0.05). To examine the effects of kimchi on immune cell growth in vitro, three types of mouse immune cells-spleen cells, bone marrow cells, thymus cells-were cultured with extracts of salted Chinese cabbage, fresh kimchi and fermented kimchi(for 1 week) for 12 or 20 days. Control was supplemented with PBS(phosphate buffer saline) excluding kimchi extract. The results of spleen cell, bone marrow cell, and thymus cell cultures showed similar tendency: control medium accelerated death of cells, extracts of salted Chinese cabbage reduced the rate of cell death, and extracts of fresh kimchi and fermented kimchi promoted cell growth. From these results, it could be suggested that kimchi possibly has an effect on the hematopoietic ability and increases immune cell development and growth in vivo.