In this study the biodiesel produced from Kapok (Ceiba Pentandra) seed Oil with methanol(CH3OH) has been considered in the presence of catalyst i.e., sodium hydroxide (NaOH), Optimum yield conditions were determined experimentally by changing the parameters of temperature, reaction duration, quantity of methanol and weight of catalyst is investigated, at the end of the experiments, the maximum yield of 95% was obtained in with the use of 21 percent methanol at 60°C reaction temperature for 2 h reaction period by catalyzing with 12g NaOH. The changes in physical property of viscosity, density, calorific value (CV) and flash point of kapok seed oil biodiesel were determined by ASTM procedures and were found to be comparable to ASTM standards for diesel fuel. GC–MS (Gas chromatography – mass spectrometry) demonstrated the presence of hydrocarbons. © 2014 Sphinx Knowledge House. All rights reserved.