Fuels from renewable sources such as biodiesel or bioalchohols are getting more attention also as blending components to fossil fuels and because of their less environmental impact. Stability and physico-chemical properties of different diesel-alcohol blends were investigated by different composition. The solubility properties of the alcohols are mainly dependent on the carbon chain length of the alcohol, their water content, additives, temperature and also on the hydrocarbon composition of the diesel fuel. Bio-butanol has better physic-chemical properties than bio-ethanol and its blends with diesel fuel have proper parameters, like Cold Filter Plugging Point and High Frequency Reciprocating Rig lubricity are close to those of the base diesel fuel.