Biodiesel is a form of diesel fuel manufactured from vegetable oils, animal fats, or waste cooking oil. It is safe, biodegradable, and produces less air pollutants than petroleum-based diesel. This paper presents the sonochemistry approach to achieve short biodiesel reaction time from jatropha curcas oil by clamp on tubular reactor. The effect of 21 mm, 60 mm diameter of clamp on tubular reactor and conventional stirring method to removing free fatty acid (FFA) and optimizing time of reaction at the acid catalyzed esterification were observed. Transesterification of jatropha curcas oil with methanol, in the sodium hydroxide as a catalyst was investigated using clamp on tubular reactor. The effect of different operating parameter such as methanol to oil molar ratio, catalyst concentration to reach optimum condition was studied. The influence of output power on water to oil concentration and time of reaction in the purification were investigated. In the esterification process, the high FFA concentration was removed lower 1% by tube of diameter 60 mm at 5 minutes time of reaction. The optimum condition of the transesterification process was achieved at molar ratios of methanol to oil of 7:1, catalyst concentration of 1%, time of reaction of 5 minutes. On the other hand the optimal condition of the purification process at water concentration of 10% (v/v), power output of 240 w, time of reaction of 5 minutes was obtained. Compared with conventional stirring method, the time of esterification reaction by clamp on tubular reactor reduces until 96%, while for the transesterification reaction reduces until 83%.