The thermodynamic properties of wide-bandgap semiconductor GaN have been investigated systematically using the concept of mean-field potential (MFP) approach and quasiharmonic Debye-model. These properties including volume thermal expansion, isothermal bulk modulus, Grüneisen parameter, constant pressure and volume specific heats and anharmonic contribution to ionic specific heat at constant volume are calculated in a wide range of temperatures (0–2500 K) for cubic zinc-blende (ZB) structure. We have employed nearestneighbour tight-binding second-moment approximation (TB-SMA) to evaluate ambient condition cohesive properties of GaN. The parameters of the TB-SMA model are derived from the fullpotential linearized augmented plane-wave (FP-LAPW) DFT-approach, obtained within the generalized gradient condition (GGA). The obtained structural and thermodynamic parameters under normal condition are found to be in good agreement with the existing experimental and other theoretical results. Meanwhile, the detailed comparison between the quasiharmonic approximation (QHA) and anharmonic-MFP models gives insight to the anharmonicity at elevated temperature. This detailed knowledge of thermodynamic behavior at high–T condition is of fundamental importance for device applications of GaN