The purpose of this investigation is to determine the effect of Zinc sulfate on growth indexes(weight ,height ,head circumference), and hepatitis B antibody titer in 28-36 week old premature neonates, born in Imam Reza and Motazedi hospitals of kermanshah. In an incidental trial, 146 neonates having no organic disease and fed only by breast milk, were entered into the study. In case of the appearance of any sign of disease, they were excluded. The newborns were divided into two groups, case and control, in a totally random fashion. The former were given 3 ml of the Zinc sulfate containing 3 mg elemental Zinc, every day for 6 months, while the latter received nothing. The weight, height and head circumference of both groups were measured at birth and both were received hepatitis B vaccine. The growth and development indexes were checked every month in both groups. The hepatitis B vaccination was done routinely in both of them .The antibody titer and the indexes were evaluated one month after the vaccination done 6th month. The results were analyzed in both groups.