Abstract: In present work, Bacillus velezensis PG1-2 producing PGA was isolated from natural soil and the fermentation medium and conditions were optimized. The best carbon source of PGA production was sucrose, and the best nitrogen source was mixture of yeast extract and peptone. The results of present work indicated that PG1-2 produces maximum PGA of 33.8 g/L when sucrose of 80 g/L, nitrogen source of 20 g/L, glutamic acid sodium of60 g/L, pH value of 6.8, throughput of 1 vvm and agitator speed of 350 r/min. B. velezensis PG1-2 could produce PGA of high yield, indicating its application value in agriculture and PGA production.