Reduction of transportation emissions and fuel consumption are important reasons motivating the development of alternative energy technologies for the internal combustion (IC) engines. Homogeneous charge compression ignition combustion (HCCI) engine is a potential candidate for higher thermal efficiency and lower emissions. The capability of burning with various fuels that have different physical and chemical properties and also the combination of different fuels as blends, are additional major advantages of HCCI engines. Ignition timing control is of great importance in homogeneous charge compression ignition engines. The effect of hydrogen addition on n-heptane combustion was investigated using a multi-zone model. Results show that hydrogen addition retards ignition timing and enhances peak pressure and temperature. Furthermore, utilizing a multi-zone model, the effects of various operating variables of a homogeneous charge compression ignition engine fueled with n-heptane and hydrogen blend are investigated in present study. Using the model a parametric investigation on HCCI engine fueled with n-heptane and hydrogen blend is conducted, in order to identify the consequence of engine compression ratio, inlet pressure and inlet temperature, on the engine performance and combustion characteristics.