Abstract: The deformation and fracture behavior under quasi-static compressive loading of a bulk metallic glass,Zr-Ti-Ni-Cu,was studied using instron universal-testing machine(IUTM) and scanning electron microscopy(SEM) at room temperature.The results showed that,the samples experience elastic and plastic deformation process before fracture,no work hardening was found during plastic deformation.Multiple shear bands were observed with more plasticity under lower strain-rate.Slipping,branching and intersecting of multiple shear bands are the main microscopic mechanisms for enhancing the plasticity.Micro-scale voids and cracks exit along the shear bands,voids growth and linkage tend to form cracks.The fracture surface is typical veinlike pattern during plastic deformation,showing different patterns under different stress states.