Abstract In-situ dendritic reinforced Dy-Fe-Al amorphous matrix composites with a diameter of 3 mm were designed and fabricated by conventional Cu-mold casting method. XRD and SEM analyses were conducted to investigate the microstructure, the mechanical properties and the deformation and fracture behaviors of the composites. The forming mechanism and the deformation and fracture mechanism of the composites were discussed. The results indicate that the microstructures of composites consist of metallic glass matrix and α-Dy dendritic phase. The composites exhibit good mechanical properties with compressive fracture strength of 1 063 MPa, which is attributed to the effective bearing-load ability of the α-Dy dendrites and the glassy matrix and the restriction to the expanding of shear bands and cracks of the α-Dy dendrites. The nature of in-situ crystalline phases embedded in the amorphous matrix for in-situ crystallite reinforced Dy-Fe-Al amorphous matrix composites has a more important influence on the mechanical properties, the deformation and fracture behavior of the composites.