The needs for high-strength and lightweight structural materials have increased in automotive and aerospace structural applications. Semi-solid processed light alloys have satisfied these requirements because of processing advantages and significant weight reduction. Conventional semi-solid casting methods have got a wide variety of problems and difficulties. The cup-cast method that has been just developed is a novel process that make semi-solid casting as easy as pouring the water from a pitcher into a drinking glass, and avoid all the problem and difficulties of other semi-solid casting processes. Cup cast method is based on the heat and mass transfer and spherical equiaxed particles with controlling the nucleation and growth of solid particles were produced. In this study the different factor of this method was optimized by micro-structural investigation on the Al-A356 alloy. Pouring height and temperature, duration of pouring, and cup coating had played important roles in this method.