A homogeneous layer of molybdenum alumininosilicide Mo(Si,Al)2 with C(40) structure was made on the sample surface of molybdenum by dip-coating technique using Al-25 mass%Si liquid at 1123 K. Adherent Al-Si was removed by soaking the dipped samples in the NaOH saturated hydraulic solution. The Mo samples coated with the Mo(Si,Al)2 layer were found to have excellent oxidation resistance in air even at 1473 K due to formation of a dense alumina film on the sample surface during oxidation. The formation of Mo5(Si,Al)3 layer was also observed at the interface between the Mo substrate and the Mo(Si,Al)2 layer.