The phase diagram of the silver-rich alloys of the ternary system of Silver-Tin-Aluminium, containing up to 30 wt% tin and up to 30wt% aluminium, has been studied by X-ray and microscopic methods.The phase section at room temperature was found to consist of four single-phase i. e. a (cubic f. c.), μ (β-Mn), β (hexagonal) and γ (rhombohedral) regions, five two-phase (i. e. α+β, α + μ ,β + μ ,β+γ and β+δ) regions and two three-phase (i. e. α+β+μ and β+γ+δ) regions. The four single-phase's appeared are exactly the same as those existing in the binary systems of Silver-Tin and Silver-Aluminium.