The current scenario in many of the countries in the world is energy importers. The largest demand occurs in energy sources especially crude products. Biodiesel is a nontoxic and decomposed organic matter. It is gathered from various sources such as animal fats, vegetable oil, and algae. In this work, the modified Soxhlet device is used as a promising new source to extract the bio-oil from Cassia javanica seeds. Throughout the study of extraction time will carried over by 3.5 hours for the production of bio-oil using hexane at 68 degrees C, by the time of 3.5 hours. The parameters of physical and chemical properties and fuel properties are analyzed by AOCS and ASTM standard methods.