Semi-solid metal alloys have a special microstructure of globular grains suspended in a liquid metal matrix that cause a significant number of benefits. A new semi-solid casting method (cup-cast method) that has been recently developed has eliminated all of the difficulties associated with other semi-solid casting processes and makes semi-solid casting as easy as pouring water from a pitcher into a drinking glass. This method is based on the nucleation and growth of solid-particles. Heat transfer phenomenon is one of the most important factors in this method that governs the shape, size, and fraction of solid particles. In this study, the heat transfer phenomena in the cup cast method has been studied experimentally and theoretically. First, the temperature distribution was measured at a semi-solid casting of Al-A356 with the cup-cast method at different points. Finally, a model for heat transfer phenomena was proposed. The final model was in good agreement with the experimental data.