15 Bacillus velezensis JT3-1 is a probiotic strain isolated from feces of the domestic yak (Bos 16 grunniens) in the Gansu province of China. It has strong antagonistic activity against Listeria 17 monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, Mannheimia 18 haemolytica, Staphylococcus hominis, Clostridium perfringens, and Mycoplasma bovis. These 19properties have made the JT3-1 strain the focus of commercial interest. In this study, we describe 20 the complete genome sequence of JT3-1, with a genome size of 3,929,799 bp, 3761 encoded genes 21 and an average GC content of 46.50%. Whole genome sequencing of Bacillus velezensis JT3-1 22 will lay a good foundation for elucidation of the mechanisms of its antimicrobial activity, and for 23 its future application. 24Keywords: Bacillus velezensis JT3-1; Genome; Antimicrobial activity; Secondary metabolite 25Province, China. Our study showed that the B. velezensis JT3-1 strain had strong antagonistic 43 activity against various intestinal pathogenic flora, and stimulation of animal (such as sheep, goat, 44 mouse, pig and cattle) growth (not published). However, there are no published reports on the 45 novel B. velezensis JT3-1 strain and its genome sequence is not found in Genebank. In this study, 46 the genome sequence of the novel strain JT3-1 was determined, the secondary metabolite clusters 47 Pandin et al., 2018). This analysis showed that at least 17% of the JT3-1 genome contributed to 99