Summary: A theoretical model for crystal melting based on the dislocation pairs is discussed in detail. The theory predicts a first-order melting transition, and the upper limit of the melting temperature is obtained. The types of dislocation mediated melting for fcc structure is different from that of the bcc one, the former mediated by the partial dislocation and the latter by the perfect one. Calculated transition temperatures, \(T_c\), for twenty-two cubic metals are close to the experimentally determined melting temperatures. As the partial dislocation mediating the lower melting point, it may give the reason of why the bcc structure is more stable than the fcc one at high temperature.