The influence of catalyst acidity, reaction temperature, and canola oil space velocity on the conversion of canola oil was evaluated using a fixed-bed microreactor al; atmospheric pressure at reaction temperatures and space velocities (WHSV) in the ranges 400-500 degrees C and 1.8-3.6 h(-1), respectively, over potassium-impregnated HZSM-5 catalysts. These catalysts were thoroughly characterized using XRD, N-2 adsorption measurements, H-1 NMR, TPD of NH3, FT-IR, and model compound reactions. Also, conditions for the production of the maximum yield of C-2-C-4 olefins from canola oil were determined, The incorporation of potassium into HZSM-5 catalyst resulted in both the dilution and poisoning of Bronsted and total acid sites. These acidity changes only severely affected the acid catalyzed reactions, such as oligomerization and aromatization, and resulted in drastic modifications in product distribution. The maximum C-2-C-4 olefin yield of 25.8 wt % was obtained at 500 degrees C and 1.8 h(-1) space velocity with catalyst K1 of relatively low Bronsted and total acidity.