The breast feeding was basic and ideal type of feed for infants especially during first six months of their life, breast feeding has a main role in infant's life as maintaining on mental and physical health, protecting from many disease and play important role in health of mothers and national and international strategies. The goals of this study is to estimate the prevalence exclusive breast feeding (EBF) in Basra (Southern of Iraq) during period of study, to determine the impact of exclusive breast feeding on morbidity of infant during first six months of life and to assess relationship between some character's for mothers and babies (Age of mothers at marriage, Age of mothers at baby birth, educational level, occupation, birth interval, methods of delivery, parity, gestational age, age, gender and birth weight of infant). The study found prevalence of exclusive breast feeding in infants for first six months of life is 54.75%, while (23.75%) and (21.5%) for partial and exclusive formula feeding respectively and showed significant relationship between diarrhea disease, respiratory tract infection and gastroenteritis and type of feeding in first six months of life at level p<=0.05. also showed EBF associated with age of mothers at baby birth, education level, occupation of mothers, and mode of delivery, gestational age and parity and found no relation between age of mothers at marriage, birth interval and sex of infant with EBF.