As an important component of diesel and kerosene surrogates, the experimental study and chemical kinetic modeling of alpha-methylnaphthalene (AMN) are still very insufficient. The ignition delay of an AMN/O-2/Ar mixture in a heated rapid compression machine (RCM) was measured in this study. The data were obtained for equivalence ratios of 0.7, 1, and 1.2, at pressures of 12, 15, and 20 bar, over the temperature range of 860-1040 K. A semi-detailed kinetic mechanism for the oxidation of AMN was established, which consists of 196 species and 1330 reactions. In comparison to the different previous mechanism, the new mechanism can more accurately predict the ignition delay of AMN in RCM and shock tube experiments. It can also accurately predict the experimental data obtained in a jet-stirred reactor from the literature. The ignition delays using adiabatic constant-volume simulation and RCM simulation were compared, which indicated that RCM simulation could better predict the experimental data. Sensitivity and reaction path analysis were also carried out to explore the effect of key reactions and paths on AMN ignition.