In order to compound refinement of primary Si and modification of eutectic Si

the Al-22 Si-Cu alloy was investigated which was prepared by the combined process using a water-cooled copper serpentine pouring channel（SPC）and Sr-modifier.The results indicate that the grain size of primary Si is refined from 90μm to 28.03μm by the serpentine pouring channel process.With increasing in the Sr content

the precipitation temperature of primary silicon is decreased

and the twin density and grain size of primary Si are both increased firstly and then decreased

which reach the maximum value with the addition of 0.09%Sr.The eutectic Si morphology is modified from acicular to fibrous.The tensile strength of the Al-22 Si-Cu alloy with the addition of 0.12%Sr reaches 212.32 MPa.