In this study, bio-oil was produced from the liquid phase pyrolysis of Giant Leucaena wood in the presence of decane solvent. Firstly experiment was conducted in an autoclave reactor at following condition; reaction temperature of 350oC, initial pressure 10 bar of hydrogen, residence time of 2 hr, biomass of 10 g and decane as a solvent of 40 g with the different catalyst types, 10% by mass of ZSM-5, NiMo/Al2O3 and Pt/Al2O3 to find the optimum catalyst type. The liquid products were characterized by GC-MS, CHN analysis and Karl Fischer titration. The result from CHN analysis showed that NiMo/Al2O3 was the optimum catalyst to produce bio-oil with lowest oxygen content, 10.02 % and the oil yield was 4.30 %wt therefore NiMo/Al2O3 was chosen for studying the influence of other parameters and find the optimum condition for bio-oil production. The influence of temperatures (250, 300, 350, 400oC), residence times (30 minutes, 1, 2, 4 hours), initial pressures of hydrogen (5, 10, 20, 30 bar), catalyst dosages (1, 5, 10, 20%wt) and reaction gases (H2, N2) were studied. It was found that the reaction temperature is the most influencing parameter for oil yield and oxygen content which were 8.60 %wt and 8.50 %, respectively at 400oC. Increase in residence time and catalyst dosage also increased oil yield and decreased oxygen content to the saturation point. The residence time of 2 hr and 10%wt of catalyst gave the lowest oxygen content and the highest oil yield. Initial pressure of nitrogen showed higher oil yield and lower oxygen content than hydrogen as reaction gas.