This investigation was designed as an overall study of breast feeding rates and corresponding influencing factors in urban and rural communities in the People's Republic of China. In all 95,578 infants between 0 and 6 months old who lived within 20 different provinces or autonomous regions were subjects for the study which was conducted from March 1983 to August 1985. The findings revealed that breast feeding rates for urban areas were significantly lower than the rates for the rural areas.