Nowadays in Indonesia Infant Mortality Rate remain high which is 51 deaths per 1,000 livebirths. The higher rates of Infant Mortality was presumed related with the pattern of breastfeeding. Exclusive breastfeeding has declined nearly 16% from 65.1% to 49.2%. There are many factors behind these exclusively breastfeeding, such as social cultural factors. The aim of this study is to know mothers behavior regarding with exclusively breastfeeding and the socio cultural factors behind these behavior. The study conducted in Karawang District, West Java Province, work area Puskesmas Ciampel and Puskesmas Tempuran. The study used qualitative approach with observation and in-depth interview to 30 breastfeed mothers. The result showed that in general breastfeed mothers were not giving their babies exclusively through the first six months of life. Early supplementation foods like honey, water and any other food to the infants pursued exclusively breastfed.