Zinc is employed in body cell growth and immune function. Zinc deficiency causes growth retardation, night blindness, delay of wound healing, skin disorders, alopecia, et al. Pharmacokinetic study of zinc in Korean has not yet been proceeded to apply to patient. In this study, we investigated to adjust zinc dosage for maintaining constant zinc optimum serum level. Five NPO inpatients (3 males, 2 females) in Seoul National University of Hospital were evaluated, retrospectively. Zinc was mixed with parenteral nutrition solution and administrated intravenously in 24 hour-continuous infusion, and zinc dosage range was 0.17-0.45 mg/kg/day. AUC to zinc dose (AUC/Dose) was $2.421pm1.007;kg{cdot}min/ml.$ 0.5 mg/kg/day zinc administration may achieve the plasma zinc concentration of $120;{mu}g/dl.$