The main problems facing worldwide especially the developing countries are the shortage and high prices of fossil fuels, therefore, searching for renewable sources of energy is highly recommended. Therefore, the conversion of biomass into alternative fuel has become one of the attracting sources of renewable energy. The bio-energy is now accepted as having the potential to provide the major part of the projected renewable energy in the future. However, there are many conversion processes such as pyrolysis, gasification, combustion, and liquefaction. Among them the thermochemical conversion (pyrolysis) which acquired special attention as it can convert it directly into liquid, solid and gaseous products by thermal decomposition in absence of oxygen. The present work will consider Jatropha curcas as the biomass source because Jatropha seeds are high energy bearing seeds available in nature. The aim of this work is to examine the fast pyrolysis process of Jatropha seeds with and without catalyst. Further, a model has been tested using experimental data measured in this study. The thermal decomposition of the Jatropha seed and the kinetics of the fast pyrolysis behavior has been investigated in the two cases using thermogravimetric analysis (TGA) at a heating rate of 20ᵒC/min in air atmosphere which indicated the range of temperature in which rate of decomposition is maximum. The results of TGA and DTG data revealed that iso-conversational free model (KAS) method gave excellent prediction with a good agreement of oil yields. The activation energies of Jatropha curcas seeds were obtained in the range of (60 to 65 kJ/mol-1) which was much lower than that of the literature (196 to 222 kJ/mol-1) concluding that the reaction rate was fast as a fast pyrolysis process already used and the correlation coefficient (R2) is 0.9987.