The deposition of Sn-5wt.%Al alloy onto pure aluminum powder in its self-convective motion by magnetron DC sputtering was examined in order to prepare Al-Sn composite particles, aiming not only at the development of highly uniform sintered binary compact materials but also at the improvement of the bonding between the aluminum particles after sintering at low temperature such as 250 degrees C. The self-convection phenomenon of the aluminum powder in the vacuum chamber occurred when a perpendicular vibration was applied to the powder. The sputter-deposition of the Sn-Al alloy was carried out during the self-convection of the aluminum powder. Under SEM and according to EPMA analysis, as well as according to thermal analysis with DSC, it was confirmed that the obtained particles were coated with the Sn-Al deposits. Therefore it was found that Sn-Al composite powder could be produced by this processing, and thereby not only the development of highly uniform sintered binary compact materials but also the improvement of the bonding between the aluminum particles after sintering at low temperature were expected.