(Cu(42)Zr(42)Al(8)Ag(8))(100-x)Si(x) (x=0 similar to 1) amorphous alloy rods of 2-6 mm diameter were prepared by Cu-mold drop casting. The thermal properties, microstructure evolution, and mechanical properties were studied by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), transmission electron microscopy (TEM), hardness test, and compression test. The XRD result revealed that all as-quenched (Cu(42)Zr(42)Al(8)Ag(8))(100-x)Si(x) alloy rods exhibited a broad diffraction pattern in the amorphous phase. The (Cu(42)Zr(42)Al(8)Ag(8))(99.5)Si(0.5) alloy was found to possess the highest glass forming ability (GFA) as well as the best thermal stability among all tested samples. In addition, both its hardness and yield strength were increased by the microalloyed Si content. The fracture strength and the plastic strain of (Cu(42)Zr(42)Al(8)Ag(8))(99.5)Si(0.5) amorphous alloy can reach 2000 MPa and 3.5 %.