The purpose of this study was to investigate the effect of dietary zinc on carbohydrate metabolism, magnesium and chromium contents of rats fed normal diet. Groups were divided three groups by zinc level of diet, such as low(15ppm), normal(30ppm) and high(60ppm) level of zinc. Serum glucose and Insulin concentrations were assessed by Glucose Oxidase method and Radio Immuno Assay method respectively. The zinc, magnesuim and chromuim contents of serum were measured by Inductively Coupled Plasma(ICP). 1. Feed intake in a zinc deficiency group was significantly higher than that in other group, but the weight gain in high zinc diet group was significantly lower than in other groups. 2. There were no significant differences in liver, kidney and spleen weight. 3. Glucose, insulin concentrations and serum zinc contents sere not significantly changed by the zinc diet at any level. However serum magnesium and chromium contents were significant decrease as the zinc level of diet increased