We reviewed the records of prematurity and birth weight infants who had been delivered at Ewha Womans University Hospital from Jan. 1975 to Dec. 1977. The results were as follows: 1) The incidence of prematurity and low birth weight infants were 53.6 and 77.3 per 1,000 newborns. 2) In delivery type, normal vaginal delivery was more frequent in prematurity and low vith weight infants than normal mature infants and c/section was less frequent. 3) The incidence of prematurity and low birth weight infants was more frequent in multiparity. 4) In the etiologic diseases of mother during pregnancy of prematurity and low birth weight infants, spontaneous premature rupture of membrane was first. 5) Initial weight loss was more prolonged and weight was regained slowly in low birth weight infants. 6) The neonatal mortality rate of prematurity and low birth weight infants was 92.5 per 1,000 prematurity and low birth weight infants and was decreased recently. 7) The relation between neonatal mortality rate and birth weight, neonatal mortality rate and gestational periods, neonatal mortality rate and Apgar score were significant. But the relation between mortality rate maternal age was not signigicant. 8) In etiology of neonatal death in prematurity and low birth weight infants, respiratory distress syndrome was first.