The purpose of this study was to investigate the effect of zinc intake on immune responses in high fat diet induced obese rats. The immune status was assessed by the measurements of immunoglobulins (IgG, A, and M) production by SRBC(sheep red blood cell) with mitogen in vivo. The delayed type hypersensitivity(DTH) response was also measured as an index of cell mediated immunity. The re sults are summarized as follows : 1) There were no significant differences in the feed intake, weight gain and feed efficiency ratio of obese rats by the different dietary zinc levels. 2) White blood cell (WBC) counts were significantly affected as the dietary zinc levels decreased. The capacity of Ig M production in obese rats was significantly higher in normal zinc group than that of low and high zinc group. Cell mediated immune response evaluated by means of DTH testing has also been found to be highly impaired by zinc deficiency and overload. From these observations, it was suggested that adequate levels of zinc may promote the immune function of obese individuals. The relationship and its functional role of the zinc in obesity remains to be further studied.