Microstructures and magnetic properties of Fe_(84)Nb_7B_9,Fe_(80)Ti_8B _(12) and Fe_(32)Ni_(36)(Nb/V)_7Si_8B_(17) powders and their bulk alloys prepared by mechanical alloying(MA) method and hot-press sintering were studied. The results show that: 1) After MA for 20 h,nanocrystalline bcc singl e phase supersaturated solid solution forms in Fe_(84)-Nb_7B_9 and Fe_(8 0)Ti_8B_(12) alloys,amorphous structure forms in Fe_(32)Ni_(36)Nb_7 Si_8B_(17) alloy,duplex microstructure composed of nanocrystalline γ- (FeNi) supersaturated solid solution and trace content of Fe_2B phase forms in Fe_(32)Ni_(36)-V_7Si_8B_(17) alloy. 2) The decomposition process of supersaturated solid solution phases in Fe_(84)Nb_7B_9 and Fe_(80)Ti_8B _(12) alloys happens at 710780 ℃,crystallization reaction in Fe_ (32)Ni_(36)Nb_7Si_8B_(17) alloy happens at 530 ℃(the temperature of peak value) and residual amorphous crystallized further happens at 760 ℃ (the temperature of peak value),phase decomposition process of supersaturated solid solution at 780 ℃ (the temperature of peak value) and crystallization reaction at 431 ℃ (the temperature of peak value) happens in Fe_(32)Ni_(36)V_7S i_8B_(17) alloy. 3) under 900 ℃,30 MPa,(0.5 h) hot-press sintering conditions,bulk alloys with high relative density(94.7%95.8%) can be ob tained. Except that the grain size of Fe_(84)Nb_7B_9 bulk alloy is large,s uperfine grains (grain size 50200 nm) are obtained in other alloys. Exc ept that single phase microstructure is obtained in Fe_(80)Ti_8B_(12) bul k alloy,multi-phase microstructures are obtained in other alloys. 4) The magne tic properties of Fe_(80)Ti_8B_(12)bulk alloy(B_s=1.74 T,H_c= 4.35 kA/m) are significantly superior to those of other bulk alloys,which is r elated to the different phases of nanocrystalline or amorphous powder formed dur ing hot-press sintering process and grain size. Microstructures and magnetic properties of Fe_ (84) Nb_7B_9, Fe_ (80) Ti_8B_ (12) and Fe_ (32) Ni_ (36) (Nb / V) _7Si_8B_ (17) powders and their bulk alloys prepared by mechanical alloying The results show that: 1) After MA for 20 h, nanocrystalline bcc singl e phase supersaturated solid solution forms in Fe_ (84) -Nb_7B_9 and Fe_ (80) Ti_8B_ (12) alloys, (32) Ni_ (36) Nb_7 Si_8B_ (17) alloy, duplex microstructure composed of nanocrystalline γ- (FeNi) supersaturated solid solution and trace content of Fe_2B phase forms in Fe_ (32) Ni_ (36) -V_7Si_8B_ (17) alloy. 2) The decomposition process of supersaturated solid solution phases in Fe_ (84) Nb_7B_9 and Fe_ (80) Ti_8B (12) alloys happens at 710780 ℃, crystallization reaction in Fe_ (32) Ni_ (36) Nb_7Si_8B_ 17) alloy happens at 530 ° C (the temperature of peak value) and residual amorphous crystallized further at 760 ° C (the temperature of peak value), phase decomposition process of supersaturated solid solution at 780 ℃ (the temperature of peak value) and crystallization reaction at 431 ℃ (the temperature of peak value) happened in Fe_ (32) Ni_ (36) V_7S i_8B_ (17) alloy. (0.5 h) hot-press sintering conditions, bulk alloys with high relative density (94.7% 95.8%) can be obained. Except that the grain size of Fe_ (84) Nb_7B_9 bulk alloy is large, s uperfine grains size 50200 nm) were obtained in other alloys. 4) The magnetization properties of Fe_ (10) Ti_8B_ (12) 80) Ti_8B_ (12) bulk alloy (B_s = 1.74 T, H_c = 4.35 kA / m) are significantly superior to those of other bulk alloys, which are related to the different phases of nanocrystalline or amorphous powder formed dur ing hot-press sintering process and grain size.