In this paper, the effect of copper and magnesium contents on the microstructure and properties of AlCuMg alloys was examined. Differential scanning calorimetry was used to study AlCu5Mg2 (0.25%Ti), AlCu5Mg4 (0.25%Ti), AlCu15Mg2 (0.25%Ti) and AlCu15Mg4 (0.25%Ti) alloys. From the obtained DSC- curves, indicating two endothermal effects, the transition enthalpy was calculated. It decreases with increasing copper and magnesium content in the alloy, for the first detectable endothermal effect. Formation of a tetragonal Al2Cu and orthorhombic Al2CuMg intermetallic compound in the investigated alloys was studied by X-ray powder diffractometry. Changes in chemical composition of the alloy caused changes in the structure reflected in the Brinell hardness and the compression strength. Compression strength and hardness increase with an increase in copper and magnesium content.