Abstract: To analyze the expression of bovine（Bos taurus） miR-19b（Bta-miR-19b） in inflammatory response of mammary epithelial cells and its potential regulation mechanism, the expression level of Bta-miR-19b was detected by real-time quantitative PCR（RT-qPCR） at 0, 3, 6, 12, 24 h after lipopolysaccharide（LPS） induced bovine mammary epithelial cells, and the function of Bta-miR-19b was analyzed by bioinformatics in this study. Compared with control group 0 h, the expression level of Bta-miR-19b was significantly down-regulated at 3, 6, 12, 24 h after LPS induction（P＜0.01）, and the expression level at 12 h was the lowest. Bioinformatics analysis showed that the mature sequence of Bta-miR-19b was highly conserved among various mammals. The 85 candidate target genes of Bta-miR-19b were significantly enriched in the biological processes such as endothelial cell apoptosis and intrauterine embryo development, as well as participated in FoxO signaling pathway, mTOR signaling pathway and PI3K-AKT signaling pathway（P＜0.05）. Protein-protein interaction network analysis showed that phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha（PIK3CA） and phosphatase and tensin homolog（PTEN） were the hub candidate target genes of Bta-miR-19b. The results suggest that Bta-miR-19b may regulate LPS-induced inflammation in bovine mammary epithelial cells through PI3K/AKT/NF-κB or PI3K/AKT/mTOR signaling pathway by PIK3CA and PTEN genes, which would provide a basis for the analysis of the molecular regulatory mechanism of dairy cow mastitis.