In this paper, nine samples of SAPO-34 Nanocatalysts were synthesized, at three temperatures (170, 190, 210 degrees C) and three times (12, 24, and 36 h) using the hydrothermal treatment and experimental design approach. All samples were characterized by XRD, SEM, FTIR, BET, and NH3-TPD techniques, to evaluate the morphology, crystal size, and surface acidity. The catalytic performance of SAPO-34 zeolites for methanol to light olefins (MTO) was investigated in a fixed-bed reactor at 410 degrees C. According to catalytic results, all prepared catalysts showed similar trends, but olefin selectivity and lifetime were greatly different. Catalysts synthesized at 170 degrees C and 24 h because of their high crystallinity, the small size of crystals and high surface area showed relatively high ethylene and propylene selectivity of 48.71% and 32.6%, respectively. Sample with low crystallinity, synthesized at 210 degrees C, and 36 h because of the existing high value of the SAPO-5 and amorphous phase, deactivate rapidly. Comparing with the other sample, the sample synthesized at 170 degrees C and 12 h because of high crystallinity, mild acidity, and small crystal size possesses a longer lifetime. Graphic Hierarchical nine samples of SAPO-34 Nano catalysts were synthesized, at three temperatures (170, 190, 210 degrees C) and three times (12, 24 and 36 h.) using hydrothermal treatment and experimental design approach. Comparing with the other sample, the sample synthesized at 170 degrees C and 12 h. because of high crystallinity, mild acidity and small crystal size, possesses a longer lifetime.