The effects of sample thickness, crystalline phase, nanoporous and temperature on the mechanical properties of Cu50Zr50 metallic glasses (MGs) under tensile loading are systematically investigated using molecular dynamics simulation method. The results indicate that the plastic deformation changes from initial homogeneous flow to a dominant shear band (SB) propagation, and ultimately again to homogeneous plastic mode mediated by a pattern of multiple SBs with increasing thickness. The plasticity of MGs can be enhanced by the introduction of crystalline phase. For MG-matrix composites, the superior tensile ductility and nearly perfect plastic flow behavior occur during plastic deformation. The results further indicate that the introduction of nanoporous leads to the decrease of the plasticity of MGs, which is due to the larger pore density. In addition, the plasticity of MGs can be enhanced with increasing temperature.