The Ti efects on the glass forming ability and the magnetic properties of Y-Fe-B-Ti bulk metallic glasses have been investigated. Substituting 2 and 4 at% Ti for Fe or B in Y6 Fe70B22 alloys decrease the saturation magnetization(αx)and deteriorate the glass forming ability,respectively. However,substitution of 2at% Ti for Y in Y6Fe72B22 alloy induces larger supercooled region of 72.TC ,which not only makes the bulk glassy rod as large as 3mm in diameter,but also results in the superior soft magnetic properties of αx=126emu/g,coercivity(Hc)=0.2 Oe and Curie temperature(Tc)=268℃. Among all Y-Fe-B-Ti bulk amorphous rods,Y4Fe72B22Ti2 displays the best glass forming ability and also the proper soft magnetic properties.