Abstract: This study aimed at identifying and exploring the diversity of lactic acid bacteria in Chinese infant gut microbiome via cultivation-based method and single-molecule real-time (SMRT) sequencing and illustrating whether antibiotic usage had negative effects on the diversity of gut microbiome. As for cultivation-based method, series diluted was used to isolate the strains of samples. Then the strains were identified through the biochemical analyses and BLAST. The phylogenetic analysis of the lactic acid bacteria was also performed. The extracted 16S rDNA was sequenced by the SMRT, then the QIIME and Mothur was utilized to analysis the diversity and structure of infant gut microbiome. The results showed that, the diversity of lactic acid bacteria in Chinese infants was really low, 32 strains were isolated by the cultivation-based method, including L. rhamnosus, E. faecalis, L. gasseri, L. plantarum, L. casei, P. pentosaceu and B. longum after identifying, strains obtained by SMRT were L. rhamnosus, E. faecalis, L. gasseri, L. casei, P. pentosaceus, L. paracasei, L. salivarius, L. paraplantarum, L. porcinae, B. pseudocatenulatum, B. longum. Only two kinds of species were isolated from the antibiotic-treatment group, including E. faecalis and L. porcinae. The diversity of lactic acid bacteria was various with the methods, and the usage of antibiotic could decrease the diversity of lactic acid bacteria in infant gut.