The (Co43Fe20Ta5.5B31.5)100-xYx（x=0.5, 1, 1.5, 2, 2.5, 3）amorphous ribbons and rods of 2 mm diameters were prepared by melt spinning and copper mold blow- casting method. The analysis of XRD and DSC test indicated that the rod amorphous of 2 mm diameter was easily prepared owing to the alloy (x=3) which the value of x is 3 with maximum glass forming ability. Because the value of the reduced glass transition temperature (Trg) and γ of (Co43Fe20Ta5.5B31.5)97Y3 alloy were 0.657 and 0.436 respectively, which were maximum in the series chemical composition investigated, the glass forming ability of Co-Fe-Ta-B alloy was assessed by Trg and γ.The results of compression test and hysteresis loops showed that the compressive fracture strength and soft magnetic property of the Co-Fe-Ta-B amorphous alloy decreased dramatically when Y was added. The compressive fracture strength and the fracture strain of (Co43Fe20Ta5.5B31.5)97Y3 amorphous rods of 2 mm diameter were 1852 MPa and 0.18%, respectively. Compared with Co43Fe20Ta5.5B31.5, the coercivity Hc was 327×79.6 A/m in the hysteresis loops of the (Co43Fe20Ta5.5B31.5)97Y3 amorphous alloy, at the same time, the saturation magnetic flux density decreased distinctly.