The purpose of this experiment is to investigate the ruminal microflora characteristics and differences between Small-tail Han sheep（STH） and Shuangqian mutton sheep（SQ）. 6 STH and 6 SQ were randomly selected,which were similar birth date,initial body weight and good health. The 16S rDNA amplicon sequencing method was applied to explore the microbial differences between the rumen of two breeds and predict the microbial function.The results indicated that the bacterial diversity and richness of rumen of Shuangqian mutton sheep are higher than those of Small-tail Han sheep. The principal coordinate analysis（PCoA） and UPGMA cluster analysis showed that the bacteria community in two groups was different. The composition of rumen microflora of the two breeds of sheep is similar at the phylum level and dominant phyla were Bacteroidetes, Firmicutes and Proteobacteria. The results of KEGG pathway analysis revealed that the rumen microbial function of SQ was mostly higher than that of STH. Based on the above analysis, the species and abundance of ruminal microflora of SQ were greater compared with STH,which could lead to higher feed utilization rate of SQ.