In the present study, the effect of Nb addition on mechanical behavior and glass formation in (Zr 56 Co 28 Al 16) 100− x Nb (x= 0, 2, 4) bulk metallic glasses was studied. The differential scanning calorimetry (DSC) was used to investigate thermal properties of samples. Further, mechanical behavior of prepared samples was analyzed using quasi-static compressive tests. The results showed that 2 at.% minor addition of Nb enhances the glass forming ability (GFA), but larger amount of Nb (4%) deteriorates GFA. The X-ray diffraction patterns also confirmed that the structures of whole of studied compositions are amorphous. In addition, the compressive test results revealed that 2% addition of Nb significantly improves compressive ultimate strength (up to 2.5 GPa) and increases the plastic strain from 1.1% in the composition having no Nb content to~ 6%. The observation of shear band branching and also the increase …