Probiotics are living microorganisms, and when consumed in sufficient quantities, they are beneficial to the host. Studies have found that breast milk contains living microorganisms, so probiotics for infants and young children are widely concerned. At present, there is no world widely clear and unified definition and consensus on “probiotics for infants and young children”. This paper described the types, common strains, safety and clinical research status of probiotics for infants and young children, and pointed out that the most studies focused on Lactobacillus and Bifidobacterium. Many reports showed that the safety of probiotics was good, but most function researches were from animal experiments, and there were few probiotics strains with mature and clear health function, especially lacking of sufficient clinical research.There were three challenges in the research and industry of infant probiotics:the contradiction between the new discovery of modern intestinal dominant flora and traditional probiotic strains, the lack of accurate mechanism analysis of health function in a deeper level like drugs, and the contradiction between the regulations of infant probiotics and clinical trial research of new strains. Although there were many problems,the incomplete gastrointestinal function and immune system of infants determined the bright prospect of probiotics development especially in China.