Fischer-Tropsch synthesis (FTS) is conducted on the catalysts such as Al2O3, SiO2, TiO2 and ZrO2 supported with metals like Co, Fe or Ru. While hydrogen to CO ratio is low, the Iron supported catalysts are more useful to produce alkenes, branched hydrocarbons and oxygenates due to Iron's water-gas-shift (WGS) activity. The aim of this article is to produce C5+ hydrocarbon product from synthetic gas using Fe-Cu-Sr/ γ-Al2O3 nano-sized catalyst. The nano iron-based catalyst was synthesized by wet impregnation method. The synthesized catalyst (18Fe/4Cu/2Sr/ γ-Al2O3) was characterized by XRD, BET, ICP, SEM and H2-TPR techniques. Effect of reaction pressure on the product selectivity and catalyst activity was investigated in CO hydrogenation reaction. The nano catalyst was loaded in a fixed-bed reactor and tested in pressure of 16 and 20 atm, at temperature of 290 oC, with H2/CO ratio of 1 and GHSV of 2 l.h-1.g cat-1. The results demonstrated that with increasing reaction pressure, the CO conversion and C5+ selectivity increased from 63.8% and 44.03% to 78.3% and 46.2%, respectively. پرونده مقاله