The ignition and flame characteristics of ethylene and blend fuel (surrogate of thermal cracked kerosene) are studied experimentally on a direct-connect supersonic combustor facility. The blend fuel consists of H2, CH4, C2H4, C2H6, C3H6and C3H8with molar fractions according to the result of gaseous compositions of thermal cracked kerosene. CH* luminance in the combustion is filmed by a high-speed camera, and unsteady process of ignition as well as flame formation and proportion is captured. Meanwhile the image of CH* luminance is one-dimensional treated along the axis of combustor and the relative amount of heat release rate of combustion is obtained. The experimental results show that with equivalence ratio increasing the flame of ethylene is changed from the cavity stabilization mode to the jet-wake stabilization mode and the combustion efficiency increases. In contrast, the total heat release and combustion efficiency of the blended fuel decrease. 漏 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.