Abstract: Auxin plays an important role in the growth and development of plant. The synthesis of indole acetic acid (IAA) is generally considered to be one of the most important mechanisms for the rhizosphere bacteria and endophytic bacteria of plant to promote the growth of plant. In order to provide reference for the development of biological fertilizer, the strains of endophytes producing IAA from tomato roots were isolated and identified and their growth-promoting effect was studied. By using the tissue grinding culture technique, twelve strains of tomato endophytic bacteria were isolated and purified from tomato roots with TSA medium as the isolating medium. The genus identification of the strains was carried out by means of 16S rDNA sequence analysis. Three strains of tomato endophytic bacteria including mr7, mr31 and B21 were randomly selected to further study their capacity of producing IAA and the growth-promoting effect on wheat. The results showed that according to 16S rDNA sequence analysis, mr7 and mr89 belonged to Enterobacter, while mr31, mr58, B21, GG1, M2, M3, r11, F127, F165 and F170 belonged to Bacillus, among which mr7, mr31 and B21 were Enterobacter cloacae, Bacillus cereus and Bacillus megaterium, respectively. The strains of mr7, mr31 and B21 had the ability to synthesize IAA directly from threonine, among which the IAA yield of strain mr7, mr31 and B21 was 67.79 mg·L^-1, 86.00 mg·L^-1 and 15.48 mg·L^-1, respectively. The results of plate test showed that the effect of strain mr7 and strain B21 after treatment was better than that of strain mr31, but the root length and plant height of wheat treated with each strain were lower than those of the control group, and there was no significant difference in the growth-promoting effect on wheat treated with different components and concentrations of bacteria solution. The results of pot experiment showed that the leaf length, root length and plant height of wheat treated with the three strains were improved to a certain extent, and they mainly promoted the growth of wheat roots, among which the strain B21 had the best growth-promoting effect. And there was no significant difference when treated with seven different inoculation methods for the same strain.