GaN-containing titanosilicate catalysts were used for the first time for the oxidative dehydrogenation (ODH) of n-butane at a relatively low reaction temperature (460 degrees C). Commercially available GaN powder with a wurtzite crystal structure showed superior reactivity and stability for the ODH of n-butane. The catalytic property of GaN catalyst for ODH strongly depends on the GaN particle size. The effects of the GaN weight percentage and GaN particle size on the catalytic performance are investigated in a fixed bed reactor. Based on the physicochemical properties of the catalyst characterized via TEM, DLS, N-2 adsorption-desorption, XRF, O-2-TPD, XRD, XPS, and in-situ FTIR, the textural and structural properties of catalyst were obtained. The catalytic results reveal that the presence of GaN increases the activity of the catalysts, indicating that GaN can be used as a new active phase for the ODH of n-butane. XRD, XPS, O-2-TPD, DLS, TEM, and in-situ FTIR results show that activated O species exist on the surface of the GaN catalyst and enhance the catalytic performance with a decreasing GaN particle size, suggesting that smaller GaN particles possess a remarkable capability to activate O species in O-2 and C-H bonds in light alkanes.