A systematic chemical lumping method has been proposed, based on the detailed kinetic analysis of hydrocarbon fuel ignitions. The model constructed by using this method contains two reaction sets, RO2 and fragment reaction package. The ignition characteristics of each fuel can be reflected by only adjusting several rate parameters in RO2 reaction package. From the comparison with detailed model, it was confirmed that this simplified model well reproduces the results of detailed one without missing the kinetics of hydrocarbon ignitions. We concluded that this new lumping approach has the possibility to be applicable to every hydrocarbon fuels.