The phase diagram of the copper-rich alloys of the ternary system of Aluminium-cadmium-copper, containing up to 30 wt % Al and up to 30 wt % Cd, has been studied by X-ray diffraction methods. The solid phase section at room temperature was found to consist of five single-phase i.e.α,γ2,δ,ζ2,and η2 regions, ten two-phese i.e.α+β,α+γ2,β+γ2,γ2+δ,β+δ,δ+ζ2,ζ2+η2,δ+η2,β+η2,and η2+θ regions, and four threephase i.e.α+β+γ2,β+γ2+δ,β+δ+η2,and δ+ζ2+η2 regions. No new phase was observed in these alloys of the system.