Abstract: Al-Si alloys have high specific strength,excellent casting property and resistances to heat and corrosion,and are extensively used in the fields such as automotive and aerospace.However,the coarse eutectic silicon and α-Al phases caused by high silicon content will have serious influence on mechanical properties and fabricating characteristic of Al-Si alloys. Based on the demand for fine control of solidification structure of Al-Si alloys,the mechanism of technology for refining grain,the development of technologies for refining solidification structure of Al-Si alloys,including chemical inoculant(such as Sr,P and RE),Si/Zr poisoning-resistant composite grain refiners(such as Al-TCB seed alloy),physical field refining and rapid solidification technology(semi-solid forming,spray deposition),were outlined.