The effects of additives including formaldehyde (CH2O) and hydrogen peroxide (H2O2) for the control of ignition of PRF/air mixture in homogeneous charge compression ignition (HCCI) engines has been investigated by direct numerical simulations (DNSs) with a 118-species pseudo reduced kinetic mechanism. It is found that the overall HCCI combustion of dual additives injection occurs at appropriate time and its mean heat release rate (HRR) is more distributed over time than those of no additive injection.