Abstract: In order to research the stress-tolerant of rhizobium isolated from Acacia nodules,15 strains of Acacia rhizobium,which were isolated from Acacia plantation growed in red soil and different ecological environment in Guangxi Province,were used as materials in this study,and their stress-tolerant to temperature,pH,NaCl and intrinsic antibiotics resistance(IAR) were compared in this paper.The results showed that there were reach strains with stress-tolerant from Acacia rhizobium.Among of them,strain S09 with superior tolerant to high temperature(39 ℃) were found.S14 were tolerant to acid(pH 4.5,5.0) and S04,S06 was tolerant to alkai(pH 9.0).Four strains could grow in media containing 1.5% NaCl.Different resistance of Acacia rhizobia to intrinsic antibiotics was proved.Strain S11 and S13 had superior resistance but S07 was poorer.All strains were not resistant to Amp.