A pure aluminum matrix composite reinforced by Bi2O3-coated Al18B4O33 whisker was fabricated by squeeze casting method. The effects of Bi2O3 coating on the whisker/matrix wettability and the ultimate tensile strength and elongation to fracture of the composite are investigated. The results show that Bi2O3 coating can react with aluminum matrix during casting process, which improves the whisker/matrix wettability. Moreover, the ultimate tensile strength and elongation to fracture of the composite attain the maximum values at the mass ratio of 40:1 between whisker and Bi2O3 coating.