Abstract: The study of a new nanocrystalline Fe^73.5Cu^0.8Nb²V^1.2Si^11.5B¹¹ alloy is reported. Using transmission electron microscopy (TEM) and M" ossbauer spectroscopy, we found that after the annealing at 843K for 0.5h in a vacuum tube furnace the alloy consists of nanocrystalline grains of bcc α-Fe(Si), about 78% in volume fraction, and residual amorphous phase. The average grain size is about 18nm. The Bs is 1.40T, the highest value of initial permeability at 1kHz (μ_e) is 71.8×10^-3 H/m, the losses at different frequencies are as follows: P_1.2/2k 21.0kW/m³, P_{1. 1/10k} 218kW/m³,P_0.5/20k 157kW/m³, P_0.2/100k 300kW/m³, and the coercivity (Hc) is about 1.1A/m. The new alloy shows obvious effect of field annealing, the B₃₀ and α₃₀ have reached 1.44T and 0.90, after annealing in longitudinal magnetic field, and 1.30T and 0.1, after annealing in transverse magnetic field respectively. Due to replacing Nb with V, the fluidity of liquid Fe_73.5Cu_0.8Nb₂V_1.2Si_11.5B₁₁ alloy and the ductility of quenched ribbon are better than those of Fe_73.5Cu₁Nb₃Si_13.5B₉, and the cost is also reduced.