The effect of Nb and Pd combination on the glass forming ability (GFA) and mechanical properties of Zr53Cu30NbxPd 9-xAl8 (x = 3.5-6.0) bulk metallic glasses (BMGs) were systematically investigated by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and compression test. TEM observation revealed that a nanocrystalline phase embeds in the amorphous matrix of the as-cast Zr53Cu30Nb 4.5Pd4.5Al8 alloy. A tiny nano-crystalline phase (with size about 5-20 nm) embedded uniformly in the amorphous matrix of the Zr53Cu30Nb4.5Pd4.5Al8 alloy was observed and identified to be the tetragonal structured NbPd 3 phase based on the analyses of nano beam electron diffraction. According to the results of thermal analyses, the composition of Zr 53Cu30Nb5Pd4Al8 and Zr53Cu30Nb4.5Pd4.5Al8 present the optimum GFA as well as thermal stability in the Zr 53Cu30NbxPd9-xAl8 (x = 3.5-6.0) alloy system. In addition, the result of compression test shows that the yield strength significantly increases from 1700 MPa (Zr53Cu 30Nb5Pd4Al8) to 1900 MPa (Zr 53Cu30Nb4.5Pd4.5Al8). A remarkable compression plastic strain (11.2%) occurs at Zr53Cu 30Nb4.5Pd4.5Al8 BMG rod with 2 mm in diameter. This significant increase in plasticity is presumably due to the restriction on shear banding by the nano-size second phase.