The energy crisis born from the oil problem determined a renewal of attention on the possible possibilities of production of substitute fuels for the operation of the machines and the thermal engines. The fuel`s production based on vegetable oils require a renewal attention about the research of replacement fuel for the opeating of machines and thermal engines. Actually, the scientific world takes an interest in the research of others liquids fuel obtained with renewables energy sources whose vegetables have a good place. So, for helping to solve the fuel problem and particularly in third world countries without petroleum resources but producing fruits and oils seed, this research was about search of fuel from vegetables oils. Extraction and physico-chemical analysis performed on various vegetables plants show an interesting energy aspect. Evaluation of actually energy parameters will permit to do a comparison with classics fuel like gas-oil and petrol. Finally, analysis of thermal engines show that fuels coming from biomass like jatropha, ricinodendron and pistacia can to use for operating of those thermal engines.