The biochemical components, enzymes, and other items from the sera and plasma of normal male and female Göttingen miniature pigs from 3 to 20 months of age were investigated. The data were compared with the normal biochemical values of rhesus monkeys, beagle dogs, and JCL: SD rats. The following characteristics were noted. 1. Activities of serum enzymes were higher and their normal ranges wider than in the other experimental animal sera. 2. Of lipid components measured, total cholesterol and phospholipid showed strikingly lower values than in the monkey and the dog. 3. The serum urea nitrogen levels were lower than in the other experimental animal sera. 4. Serum creatinine and potassium were present at relatively high levels, with wide normal ranges. 5. There was a tendency with advancing age toward lower alkaline phosphatase and higher total protein and creatinine. 6. Leucine aminopeptidase was higher while total cholesterol and phospholipid were lower, in the male than in the female. 7. The electrophoretic patterns of serum protein and lipoprotein differed markedly among the species.