Abstract: Breast milk covers all kinds of nutrients for infant growth. In order to guarantee the infant growth healthy and rapidly,breast- feeding is the best way. Traditional culture and modern molecular biology techniques have showed that breast milk is the natural source of lactic acid bacteria.The immune system plays a crucial role in the process which lactic acid bacteria are transferred from intestinal to mammary gland.So far the lactic acid bacteria that can be isolated from the health of maternal breast milk are Streptococcus,Lactobacillus,Lactococcus,Enterococcus,Bifidobacterium,Leuconostoc,Pediococcus,etc. Many studies indicate that some lactic acid bacteria species in breast milk have special functions,such as inhibiting the growth of pathogenic microorganisms,regulating immune system and mammary gland flora,anti- HIV and curing mastitis and so on.The source,transmission between mother and baby,species and functional characteristics of the breast milk lactic acid bacteria were reviewed in this paper. And the references for the further research and utilization of lactic acid bacteria in breast milk were also provided.