Biohydro-fined diesel (BHD) is the second generation Biodiesel (BOD) which is also carbon neutral biomass fuel more effective in CO2 reduction. The quality of BHD is same as conventional petro diesel fuel; therefore, BHD can be used without any modification of infrastructures and vehicles. Vegetable oil has boiling point of around 600 degrees C and not suitable for diesel engine motor vehicles. But the vegetable oils are hydrogenated by carrying out the Biohydrogenation or Biohydro-fining process resulting in hydrocarbon nearly equal to petro diesel called BHD. In the hydrogenating process, vegetable oils are decomposed down to a molecular weight equivalent to the components contained in diesel fuel, and unsaturated hydrocarbons contained in vegetable oil are converted to saturated hydrocarbons. In the hydrogenation reaction of vegetable oil, it is observed that, in conditions in which complete hydrogenation of the unsaturated bonds is reached; the complete hydrodeoxygenation of the oil was also reached. Moreover, hydrodeoxygenation reactions include a dehydration reaction in which oxygen is eliminated as water (H2O), and a decarbonation reaction in which oxygen is eliminated as carbon dioxide (CO2), both reactions were occurring in this processing. To eliminate a given quantity of oxygen, less hydrogen is consumed in decarbonation than in dehydration. At such time when, through optimization of reaction conditions and catalysts, it becomes possible to control the hydrogenation reaction, one should select a reaction system based on which is best overall with respect to issues of hydrogen consumption, byproducts, and LCA CO2. BOD is composed of long-chain fatty acids with an alcohol attached, often derived from vegetable oils like fatty acid methyl ester (FAME). It is produced through the Transesterification reaction of a vegetable oil with methyl alcohol or ethyl alcohol in the presence of potassium hydroxide (KOH) or sodium hydroxide (NaOH) catalyst, which produces biodiesel and glycerin. BHD has a good oxidization stability as same as conventional diesel fuel unlike BOD. BHD has the same components as those contained in conventional diesel fuel. BHD is characterized by its high cetane index, zero sulfur, and zero aromatic carbons, presenting a possibility that it can more effectively reduce the exhaust gas (PM, NOx) than conventional petro diesel fuel when used in combination with appropriate motor vehicle technologies. Currently FAME contains high viscosity and double bond. Biohydrofining of vegetable oil appears to be a better option than Transesterification in producing diesel substitute because of high oxidation stability, low viscosity and disappearance of double bond in structure in BHD. However the cloud point of the hydrogenated oil is slightly worse than FAME warrants improvement considering the cold flow property requirement. The cold flow property of BHD can be improved by using hydroisomerization technologies with two kinds of noble metal catalysts (amorphous type and zeolite type).