The study was conducted in order to promote the accuracy of vital statistics about infants, and to obtain infant birth information more rapidly and completely. Infants born in Taipei County from May 1, 1984 to May 31, 1984 were selected as our study sample. Both health professionals and officials of household administration agencies in the study area were asked to provide infant birth information. After matching these 2 resources of infant birth information, the unregistered infants were recorded and followed their survivorship up for one year after their birth by public health nurses. Based on the infant birth data collected, we found: I. Under current household registration regulation, most birth registrations were with some delay. II. The estimats of various death rates about infants are as follows: 1. Late Fetal death rate: 8.27%-12.42% 2. Perinatal death rate: 16.55%-21.01% 3. Neonatal death rate: 8.60%-9.46% 4. Infant mortality rate: 11.12%-14.91% The estimated infant mortality rate much higher than official report (6.34% 1983) The findings suggested the necessity of including health professionals to the birth registration system, and the importance of studying the feasibility of implementation of this modified system in the Whole Taiwan Area.