This paper aimed to get the insights of consumer behavior in formula milk market. By implementing a survey with sample size of 97, the research investigated the factors influencing behavior of formula milkbuyer. Research examined and approved that all 4 factors (cultural, social, personal and psychological factor) equally influence on purchasing formula milk for babies in Hanoi. Research also concluded that domestic formula milk producers should attain their customers by committing high quality, adding more values for nurturing babies, setting right price, and providing sufficiently information.