Plastic deformation and damage accumulation at the contact surface are two important aspects of sliding wear of metal-matrix composite (MMC) materials such as AlSi alloys. The particular topography of the surfaces of the AlSi alloys has triggered the idea that the silicon particles form a load bearing surface over which the countersurfaces are sliding. Therefore, the wear resistance of AlSi surface is thought to originate from the high hardness of the silicon surface formed by the primary Si particles (inclusions). On the other hand, the mechanical strength of the reinforcement (Si)/matrix(Al) interface in a MMC is the primary factor determining the strength on the load bearing Si formation. In this work, the authors developed a novel method to characterize the interface strength of a MMC, combining a nano-/microindentation experiment and a finite element/atomistic analysis. The nano-/microindentation experiment was carried out by indenting individual reinforcement particles on a free surface with a nano-/microindenter. The dependence of indentation response on the interface properties was systematically studied, and the interface strength was extracted from the threshold stress for the sink in of the Si particles. With this method, the shear strength of an Al/Si interface was measured approximately 330 MPa, which compares well with the lower bound of an atomistic simulation with a modified embedded atom method potential [A. Noreyan , Acta Mater. 56, 3461 (2008)].