The present research had dealt with preparing aluminum alloy matrix (Al-4.5%Cu-1.5%Mg) by cast and to proceeding the heat treatment solution from different temperatures 500oC, 525oC and 550oC for different times 2hr and 4hr, and then proceeding the requil hardness (HBR), Therefor we conducted the optimum value from the alloy basic(A) at the temperature 550oC for 4hr time. Also we prepared the matrix composite reinforced by alumina (Al2O3) with different percentage weight (1.5%-2.5%) and three different particles sizes (75µm≥65µm≥53µm≥0.1µm) which named as (A1, A2, B1, B2, C1, C2) according to their weight and size percentages, and then proceeding the heat treatment solution and official ageing about them at the temperature degree 550oC for 2hr and4hr. Mechanical tests like hardness and impact resistance were conducted all of them reached that the composite material (A2) in which there weight and size percentages are 2.5% and ≥0.1µm have upper values of these test's, accordingly we concluded that the reduce particles means increased its rigidity, toughness and solidity. Finally the microstructures tests shows that the prepared composites materials have small size as compared with microstructure of the basic cast alloys and the distribution of alumina particles was fairly homogeneous in the basic allot, also we showed that the heat treatment solutions and official ageing are affected at these composite materials and alloys.