Synthesis of dinitrate compounds from alkane diols, such as 1,6-hexane diol, 1,8-octane diol, 1,10-decane diol, and 2-methyl-2,4-pentane diol could be prepared by direct nitration reaction. The nitration took place by using mixed acid containing concentrated nitric acid and concentrated sulfuric acid in the presense of solvent. The dinitrate compounds obtained were identified by spectroscopic techniques, such as Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy. They could be easily blended with base diesel fuel. From the determination of cetane index, they could increase cetane index about 3.9 and 6.3 units at the concentration of 0.05% and 0.10% by weight, respectively. From the prediction of cetane number, they were more effective than commercial cetane improver at both concentrations of 0.05% and 0.10% by weight, especially 1,10-decane dinitrate. These dinitrate compounds had potential to be used for improving cetane number of basediesel fuel.