Chromium and aluminum added Mo3Si compounds were fabricated by arc melting method so that the alloy composition corresponds to Mo(75-y)CrySi(25-x)Al.; i.e. the apparent compound type of (Mo,Cr)(3)(Si,Al). The influences of the concentration of Cr and Al on the phase construction, mechanical property and the oxidation behavior were investigated. It was found that the solubility limit of each Cr and Al for Mo3Si is small. During oxidation test, the mass of plate like specimen Of Mo3Si decreased remarkably and was decreased with increasing Al concentration. The Cr addition of no more than 15mol% effectively improved the oxidation- proof properties in Mo3 (Si,Al) compounds.