The interaction between an eccentric matrix crack and a circle inclusion in composites is investigated numerically to explore the strain rate effects on the crack deflection/penetration behaviours at the matrix-inclusion interface. It is found, with the increase of strain rate, that there will occur in turn the crack deflection, the double-crack fracture and the crack penetration processes for a certain material. Moreover, both higher relative interfacial strength and smaller eccentric angles can redound to the crack penetration. Additionally, it is demonstrated that the strain rate effect on the composite strength is a local structural response characteristic rather than an intrinsic material property, which sounds in agreement with that proposed by previous authors.