The main objective of this research was aimed to study the cracking of crude palm oil to liquid fuel by using HZSM-5 as catalyst in a micro reactor by varied operating conditions as reaction temperature 380-450 oC, reaction time 30-60 min and mass of HZSM-5 0.25 - 2.5 % by weight with initial hydrogen pressure 100 psi. From the results, it was found that the reaction temperature, reaction time and weight of HZSM-5 catalyst were significantly affected to the oil yield. The analyzed oil product from simulated distillation gas chromatography was found that the reaction temperature is 425 oC and the reaction time is 30 min at initial hydrogen pressure 100 psi. This was the optimum condition of thermal cracking that gave the highest yield of naphtha. The oil yield was 79.96 % by weight, 37.22 %Naphtha, 13.07 %Kerosene, 16.48 % Light gas oil, 1.93% Heavy gas oil and 11.27 %long residues respectively. In case of using HZSM-5, the analyzed oil product was found that reaction temperature 410 oC reaction time 60 min by using HZSM-5 1.0% by weight was the best condition. The oil yield was 68.57% by weight, 22.97 %Naphtha, 11.31%Kerosene, 24.55% Light gas oil, 1.30% Heavy gas oil and 8.43 %long residues respectively.