The effects of varying quantity of Al-10Sr and Al-5Ti- 0.2Cwith separate or simultaneous addition on the microstructure of ZL101 alloy at different holding time were examined by means of OM and SEM. The results showed that 0.5% addition of Al-10Sr to the alloy leads from coarse needle-like or flake-like eutectic Si morphology to fine short fibrous one and prompts the nucleation and growth of the dendritic α-Al phase with grain size varying between 100 and 250 μm. 0.2% addition of Al-5Ti-0.2C also can modify eutectic Si to some extent and generate equiaxed primary α-Al phase with about 40～70 μm. Simultaneous addition of both Al-10Sr and Al-5Ti-0.2C can refine and modify both α-Al phase and eutectic Si

which is attributed to the interactive effect of refinement and modification of Al-10Sr and Al-5Ti-0.2C.