Abstract: Based on the chemical thermodynamics and kinetics theories, the parent alloy of an in situ reaction system is studied first, and then the TiC-AlN/Al composite is produced by the direct carbonization and nitrogenation of Al-Ti-Mg alloy in the condition of electromagnetic and gas turning mixings. According to the compositions of elements and phases of the kinetics samples taken from the vacuum furnace in different reaction time and measured results of PO₂ in the furnace, the effects of furnace atmosphere on the reaction process and the reacted reactants are analyzed.