In this research, we studied the isolation of the cellulolitic fungi from soils around the persimmon tree, grapevine, pomegranate tree and walnut tree. From among them, persimmon tree soil was selected because of the presence of maximum cellulolitic fungi. Of the seven fungi isolated from persimmon soil, three had suitable cellulose activity and they were identified by 18S rRNA and named: Aspergillus niger MZM 89-a2, Penicillium decumbens ZHE 89-p3, and Penicillium decumbens MMH 89-p1. Cellulose activities of these fungi were respectively (U/d): FPA 3.1671, 3.5740, 3.1812, Avicelase 1.6605, 0.3869, 1.1451 and CMCase 2.950, 0.2644, 0.4604. Response surface methodology (RSM) was used to evaluate the effects of temperature, moisture content and particle size on FPA and CMCase activity by Aspergillus niger MZM 89-a2. Statistical analysis of the results for Aspergillus niger MZM 89-a2 showed that temperature and particle size had significant effect on FPA and CMCase activities. Maximum were obtained at   25°C temperature and 0.5 mm particle size for FPA and 35°C temperature and 0.5 mm particle size for CMCase.