Ag-Sn(9.7-χ/10)-In(χ=0,0.5,1.0,1.5,2.0) alloy powders were prepared by atomization. Within the Ag-Sn-In alloy powders were oxidized in air. The experimental indicates show that the oxidation rate of the samples of χ = 0.5 was always lower than that of the samples of χ = 0, a little added In cannot promote the increase of oxidation rate, instead inhibits its oxidation. The oxidation rate of the samples of χ = (1.0,1.5,2.0) varies oddly. When the temperature is below 700℃, their oxidation rate is higher than the samples of χ = 0 obviously, while the oxidizing temperature and holding time reaches a certain parameters, the oxidation rate of samples of χ = 0 is better. It shows that when it is at low oxidizing temperature for short time, added In of χ = (1.0,1.5,2.0) is good for oxidation reaction, but at high temperature oxidation for a long time, the effect of the additive In is not big, even negative on the oxidation reaction. According to the comprehensive test, we explore and conclude that the reasonable oxidizing temperature which the various samples can obtain a better oxidation rate is at 750 ℃.