PURPOSE: Acquisition of varicella by the neonate as a result of congenital varicella-zoster infection or exposure during delivery is well known. And it generaly believed that infants under 6 months of age may acquire varicella more frequently than other viral infections such as measles. However, little if known about immune mechanism of varicella-zoster infection. Transfer maternal antibodies to this virus through the placenta and their persistence in the newborn sera has not yet been studied in healthy mother and children. METHODS: We estimated VZV antibody titer in 62pairs of maternal and cord blood by IAHA, FAMA and ELISA methods. The purpose of study was to evaluate sensitivity of methods and determine the level of VZV antibody in neonates. The results were as follows. RESULTS: 1) The titration of antibody of VZV was performed by IAHA, FAMA and ELISA mothods. There is no different significance by each methods and linear correlation among IAHA, FAMA and ELISA mothod is significant. 2) The VZV antibody titer of neonates is no significant according to sex and birth weight. 3) By the FAMA method, the VZV antibody titer of fullterm neonates is significantly higher than preterm. 4) The titer of VZV antibody is elevated to increse with gestational age, but there is no significant difference. 5) The mean ratio of cord/maternal sera level of VZV antibody titer is no significance according to gestational age. CONCLUSIONS: Further epidemiologic study of VZV infection showed be investigated in Korea.