Direct catalytic cracking of biomass pyrolysis vapor into aromatics derived from Douglas fir sawdust pellets was tested using an upfront microwave pyrolysis process coupled with a packed-bed catalysis process using a ZSM-5 Zeolite catalyst. A central composite experimental design (CCD) was used to optimize the bio-oil and syngas yields. The effects of temperature and inverse weight hourly space velocity (WHSV)-1 on the bio-oil composition were determined. GC/MS analysis results showed that the bio-oil contained aromatic hydrocarbons and no oxygen containing compounds. Aromatic hydrocarbons were enriched and become the most abundant compounds accounting for about 15-92.6% in upgraded bio-oils depending on the catalytic pyrolysis conditions. The aromatic hydrocarbons were mainly composed of benzene, toluene, xylene, naphthalene, and there derivatives. When the effect of reaction temperature on bio-oil chemical compositions was analyzed with a fixed (WHSV)-1 (0.048h) we found that the aromatic hydrocarbons were increased from 0.72% in raw bio-oil (no catalyst added) to around 92.6% when the catalysis temperature was 500°C clearly demonstrating that high temperature with the ZSM-5 Zeolite catalyst favored the production of aromatic hydrocarbons. At a lower temperature fixed at 375°C, the aromatic hydrocarbon content was increased from 0.72% to 78.1% with (WHSV)-1 increase from 0 to 0.075.