A new Y6Fe60.5Co11.5B22 Fe-based bulk metallic glass with a maximum diameter of 2 mm has been fabricated by suction casting method in a water-cooled copper mould. The interrelationship between cooling rates and magnetic properties were investigated and the critical cooling rate of the amorphous alloy was calculated. The bulk amorphous alloy has a coercivity of 2.53 A/m,a saturated magnetization of 1.24 T,and a high initial susceptibility. The critical cooling rate (Rc) of the Y6Fe60.5Co11.5B22 amorphous alloy was determined to be about 119 K/s.