An in situ CuZr-based metallic glass matrix composite containing B2-CuZr phase was prepared by arc melting and injection casting. Mechanical behaviors of the composite under uniaxial compression were investigated over a wide strain rate range (2.0 x 10(-4)-3.6 x 10(3) s(-1)). The composite exhibited obvious work-hardening behavior, considerable plasticity, as well as positive strain rate sensitivity under quasi-static compression, which is attributed to the deformation-induced martensitic transformation and formation of multiple shear bands. In contrast, the composite failed by catastrophic fracture with nearly no macro plasticity and exhibited negative strain sensitivity under dynamic compression, which is owing to the strain rate softening of the amorphous matrix.