Abstract: In the ranges of f=3-30kHz and B_m=0.1-1.0T, the behavior of medium-frequency P/f vs f was investigated for Fe₇₃Cu₁Nb₂V_1.5Si_13.5B₉ alloy with high B_r. The dependence of the numbern of "Magnetic Object"on the excess field Hexc was investigated in the medium-frequency range. The results indicate that the non-linear behavior of medium-frequency loss can quite well be described in terms of the relevant equations and parameters in the statistical theory of loss. In the ranges of f=30-1000kHz and B_m=0.05-1.0T,the behavior of high-frequency P/f vs f was investigated. The behavior of P/f vs f shows quasi-linear in the considerably wide range and be expressed by thelinear equation P/f=P_eh+K_eclf quite well. The examined high-frequency range can roughly be divided into two ranges, inwhich K_ecl and P_eh possess different values. A series of calculations indicate that the loss decomposition in the light of P/f=P_h+P_clf+P_exc/f and the relevant equations in the statistical theory are inapplicable to correctly describing the behavior of the high-frequency loss.