Azotobacter chroococcum is a free-living N2 fixing bacterium potentially beneficial for plant growth. Apart from fixing nitrogen asymbiotically, this bacterium has also the ability to synthesize and secret different kinds of plant growth promoting compounds essential for plant growth, therefore it is considered as Plant Growth-Promoting Rhizobacteria (PGPR). In this study, the potentials of native strains of Azotobacter chroococcum to promote plant growth was evaluated using in vitro tests. First, soil samples were taken from the rhizosphere of irrigated wheat in 63 wheat fields of Chaharmahal from Bakhtiari province and then native strains of Azotobacter chroococcum were isolated, identified and counted. Second, the purification of Azotobacter chroococcum isolates were carried out, and in vitro tests including the ability to produce indole-acetic acid (IAA), siderophore, hydrogen cyanide (HCN), the ability to solubilize mineral and organic insoluble phosphates and nitrogen fixation were conducted. Results showed that Azotobacter chroococcum population varied among the wheat fields, being the highest in Choghakhort wheat fields and the lowest in wheat fields of Jooneghan area. Results indicated that most isolated strains were capable of producing IAA, siderophore, and HCN, and fixing nitrogen. However, they were not able to solubilize mineral and organic phosphates. Therefore, the production of IAA and nitrogen fixation would be the major function of native isolates, and thus their presence in the rhizosphere could improve wheat growth and yield. Overal, based on the obtained results in this study, only some strains of Azotobacter chroococcum native to wheat fields of Chaharmahal in Bakhtiari are recogilized as PGPR.