Single domain GdBCO bulk superconductors,with compositions of GdBa2Cu3O7-δ(Gd123):Gd2BaCuO5(Gd211):Gd2Ba4CuNbOy(GdNb2411)=1:(0.4-x):x,have been fabricated successfully by the topseeding melt texture growth process(TSMTG),x=0,0.02,0.06,0.1,0.14.four kind of GdNb2411 particles with different size(d),0≤d≤40mm、40