Abstract: The effect of Al-Ti-C content on the microstructure and mechanical properties of the hypereutectic Al-20 wt%Si alloy was studied. The results show that Al-Ti-C master alloy is mainly composed of Al₃ Ti, Ti C and Al matrix. Al-Ti-C can effectively refine the size and morphology of primary Si. When the content of Al-Ti-C is 0.9 wt%, the primary Si in Al-20 wt%Si alloy is refined from coarse irregular long block to fine short block; the elongation and tensile strength of Al-20 wt%Si alloy reach the maximum, which is 1.6% and 132.5 MPa, respectively.