The effect of refrigeration in 4 ℃ on bacterial communities and its succession within raw milk was studied by using high-throughput sequencing. During stored at 4 ℃ for 6 days， the microbial communities in the raw milk were characterized using the Illumina Miseq platform. The result showed that the microbial communities had been changed over time during storage. There were 29 OTUs obtained in each samples， and there were 157 unique OTUs at the beginning of refrigeration which were the largest number. The dominant bacteria in raw milk were Acinetobacter， Lactococcus， Flavobacterium， and Pseudomonas， and the abundance of each genus changed during the change of refrigeration time. Acinetobacter was the largest population at the early stage of storage， which was 81.69%. After fluctuation， it decreased to 37.02% at the end of storage. In the other hand， Lactococcus increased from 1.45% at the beginning to 53.34% at the end of refrigeration storage， and became the largest proportion. The results from this study will provide the basis statics for raw milk， and expected to aid in improving the quality and safety of raw milk.