Molecular dynamic simulation was used to study the melting behavior of gallium nitride (GaN) nanowires with the Stillinger-Weber potential. Our results reveal that the melting of the nanowires starts from the surface and rapidly extends to the inner regions of nanowires as temperature increases. The melting temperatures increase to saturation values ∼3100 and ∼2900 K when the diameters of nanowires are larger than 3.14 and 4.14 nm for the nanowires with [100]- and [110]-oriented lateral facets, respectively. The saturated values are close to the melting temperature of bulk GaN. The low melting temperature of GaN nanowires with small diameter may be associated with the large surfaces of nanowires.