The aim of this study was to analyze the gut microbiota differences of forest musk deer juveniles (n=10) and adults (n=10). To gain insights into this, total DNA was extracted from fresh fecal samples and the microbial composition was characterized by sequencing V3-V4 hypervariable regions of 16SrRNA gene using an Illumina MiSeq 300PE in pair end mode. Sequencing data were processed for quality control and microbial operational taxonomic units (OTUs) were assigned. To access gut bacterial enrichment and differences, alpha-diversity indices were calculated with respect to age. The abundance and diversity of microbes in the adult group were slightly higher than those in the juvenile group, but not statistically significantly so ( P > 0.05). The dominant gut microbiota mainly belonged to the phyla Firmicutes, Bacteroidetes and Proteobacteria in both groups. In particular, a significantly greater proportion of Proteobacteria and a lower proportion of the Firmicutes were found in the adult group. LEfSe analysis revealed 12 distinct bacterial classifications. Both adult and juvenile forest musk deer showed significant differences in the composition of Proteobacteria and Firmicutes. This study shows evidence that there are no signif-icant differences in the abundance and diversity of gut microbiota among adult and juvenile forest musk deer. Further, the composition of bacteria is remains the same, but the proportion of bacteria in the two groups was different which indirectly reflects the different necessity of nutrition ab-sorption at different ages.