The single crystal NiAl2O4 was prepared by a solid-state reaction. The change of its cation distribution with temperature was calculated by a modified thermodynamic equation by including a new parameter delta, which is a characteristic of nonconfiguration entropy. The calculated results showed that the degree of inversion for NiAl2O4 decreases with temperature, although the temperature dependence of cation distribution is very weak. This result was supported by X-ray diffraction measurement.