With the object of developing a new magnetic core materials for high frequency use, the crystallization behaviors and the soft magnetic properties of amorphous $F_{86-x}Al_{4}B_{10}Zr_{x};(5{leq}x{leq}10;at%)$ alloys subjected to annealing treatment at wide temperature range were investigated. For optimally annealed $Fe_{86-x}Al_{4}B_{10}Zr_{x}$ alloys in amorphous state, rather good soft magnetic properties of ${mu}_{e}=17000~25000,;H_{c}=20~30$ mOe and $B_{10}{geq}0.6$ T are obtained. However, as the alloys crystallize, the soft magnetic properties are largely dergely deteriorated, which is attributed principally to the narrow temperature gap between $T_{x1}$ and $T_{x2}$, which allows the nearly co-precipitation of bcc phase and Fe-B compounds in incipient crystallization stage.