The chemical mechanisms have direct relationship with combustion, so the research of mechanism has been attended by researchers. The aim of article is to compare n-heptane, n-dodecane, n-tetradecane, n-hexadecane, which can give a direction for alternative fuels. This article compared the performance of alkanes in different conditions, such as shock tube and HCCI. The results show that difference of ignition delay time is relatively little at two ends of temperature. The large difference can be found in NTC range, especially the pressure is 13.5 atm and equivalence ratio is 1. The results also show that the trends of main species are same for different alkanes. The increasing time of CO and H2O2 are earlier than that of others for the n-tetradecane. The changes of in-cylinder temperature and pressure are same for alkanes with increasing equivalence ratio and inflow pressure.