The ignition behavior of blended fuels created by mixing different pro-portions of any of the three commercial liquid fuels, gasolene,--kerosene and light diesel fuel, is investigated using the shock tube technique. The ignition delay of the blended fuels, based on the pressure rise criterion, is measured over a wide range of pressure, temperature and equivalence ratio. The results indicate that for all blends the thermal ignition delay decreases with the increase of temperature and pressure. The results also show that blending a heavy liquid fuel, containing high percentage of low boiling simple aromatics and naphthenes, results in remarkable decrease in ignition delay. The experimental results of the various blends are correlated using the following Arrhenius form T. (A/pn)meE/RT The pressure exponent is found to be the same for all different blends; its value is calculated to be 1.05. The exponent of the equivalence ratio changes its sign from negative in the lean region to positive in the rich region. The activation energy of all different blends are also calculated.