There are several factors which influence the human organism from the moment of conception and may cause its loss. Of these the maturity of an infant is considered to be a vital determinant of its survival. This article explores the distribution of survival time and its relationship with birth-weight, gestational age, race and sex. The distribution of survival time is described by a Weibull distribution and Glim is used for analyzing grouped censored survival data with concomitant information developing Aitikin and Clsyton's method (1980). The methods are found to fit and the variance covariance and correlation matrices are calculated for the parameters included in these models. The mortality rate is calculated for each group of survival time, birthweight, gestational age, sex and race.