This study was conducted to establish a rapid, sensitive and economical method for the large scale measurement of immunoglobulin G(IgG) concentrations in porcine serum. An enzyme-linked-imrnunosarbent assay was described for the estimation of porcine IgG in serum samples. A series of known IgG concentrations (0, 0.1, 1, 5, 10, 25, 50 ㎍/㎖) were prepared as standards. The determination coefficient of our standard curve (R²=0.99) was high and the intra- and inter-assay coefficients of variation ranged from 0.5%o to 1.5% and from 1.6% to 5.4%, respectively. The correlation coefficient between known concentrations of IgG and those determined by the ELISA method (r=0.997) was higher than RID method(r=0.985). These results indicate that serum IgG concentrations assessed by the ELISA method can be used accurately. The IgG level in pig serum, which was 0.05 ㎎/㎖ at the time of birth, increased rapidly in 24 hour post partum (33.1 ㎎/㎖), and then decreased gradually up to 4 weeks of age(6.6 ㎎/㎖).