A series of FeZrB alloys with different nominal compositions were prepared by melt-spinning and then annealed at their first crystallization temperatures, respectively. The thermal curve, microstructure and magnetic property of alloys were investigated by simultaneous thermal analyzer (STA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The results show that the primary crystallization phases are different with the compositions of FeZrB alloys changing. Four groups of primary crystallization phases can be observed in the alloys, i.e. α-Fe phase, α-Fe+Fe23B6-type phases, α-Fe+α-Mn type phases and α-Fe+Fe2B+ZrB phases, and their morphologies are of different by TEM. The relations of saturation magnetization (Ms) and coercivity (Hc) for the alloys with different primary crystallization phases are as follows: Ms(α-Fe)>Ms(α-Fe+α-Mn type)>Ms(α-Fe+Fe2B+ZrB)>Ms(α-Fe+Fe23B6-type) and Hc (α-Fe+α-Mn type)>Hc(α-Fe+Fe2B+ZrB)>Hc(α-Fe+Fe23B6-type)>Hc(α-Fe).