The surface phenomena of Pb97.4Sn2.6 alloy under the Ar+ ion sputtering have been investigated using PHI-590 scanning Auger microprobe at room temperature. Theoretical analyses of experimental data showed that the ion-bombardment-enhanced diffusion occured with diffusion coefficient up to 10-15 cm2/s and the thickness of alter layer was about 260 ?. The possible explanation is given.