Experiments were carried out with 307 isolates collected from pistachio rhizosphere in Rafsanjan, Kerman, Sirjan and Zarand. In this study, from a total of isolates collected from pistachio rhizosphere, 21 isolates (from gram positive bacteria) and 10 isolates (from fluorescent Pseudomonads) showed antagonistic effect on P. citrophthora using in culture test. After preliminary labortory tests, six highly effective antagonists were selected for subsequent studies. Based on physiological, biological and morphological tests, isolates, 23 and 85 were identified as Bacillus cereus, isolates, 8 and 291 as Pseudomonas fluorescens (biovar III) and isolate 126 as Bacillus subtilis. Bacillus isolates prevented mycelial growth of the through volatile metabolite productions and isolate 126 was much more inhibitory to in vitro mycelial growth by volatile metabolites. Antibiotics produced by isolates 8, 291 and CHA0 prevented mycelial growth of the fungus. Volatile metabolites produced by isolate 8 had more effective on inhibitory mycelial growth in PDA medium and isolates had not significant effect in NAG medium. Isolates 8, 291 and 126 produced siderophore on CAS-Agar medium and only P. fluorescens produced hydrogen cyanide. In a greenhouse study, isolate 126 had the greatest effect on decreasing disease and increasing of growth factors in sterile and non sterile soil.