Spherical powders of aluminum oxynitride/nitride are directly prepared by flame synthesis in which oxygen serves as an indispensable reactant. Nonoxide powders are commonly nonspherical, and the particle sizes of these powders are less than submicrometers. The major limiting factors for the synthesis are the free energy, reaction temperature, and reaction rate. The innovative issue related to this flame technology that is assisted by plasma is the ambivalence of the reducing gas atmosphere over 1500 K. The chemical equilibrium calculated indicates that the plasma heating compensates for the lack of reaction temperature under a low-oxygen condition. This burner realizes a high-speed reaction with the help of the reactive species in the arcs.