To investigate the possibility of inoculating eutectic cells, a novel Al-10Si-2Fe master alloy was synthesized and tested in Sr-modified A356 alloy. The new master alloy that consists of メ-Al, Si and モ-Al5FeSi phases was prepared by a casting process, and the silicon phase was found to grow epitaxially from the モ-Al5FeSi particles. The inoculation efficiency of the new master alloy on Sr-modified A356 alloy has been investigated by quenching experiment and thermal analysis. With the addition of the new master alloy, the area density of eutectic cells is effectively increased by 100% and the eutectic growth temperature is increased by 1.5 ìC. Therefore, the new master alloy is deduced to introduce nucleating substrates for eutectic cells and to refine the eutectic cells in Sr-modified A356 alloy. There is no poisonous interaction between the Al-10Si-2Fe master alloy and the Sr in this study. Consequently, the mechanical properties have been improved by the addition of the new master alloy.