Amorphous alloy composite is designed to prevent rapid propagation of shear bands in amorphous phase by introducing the second crystalline phase, which can improve the plasticity of alloy. In situ formed amorphous alloy composites have attracted much interest due to excellent properties and extensive application prospect, especially the dendrite reinforced amorphous alloy composite with excellent tensile plasticity. Recent studies show that the plastic deformation behavior of amorphous alloy composite is not only related to the mechanical properties of the crystalline phase, such as elastic modulus, but also with the size, volume fraction and morphology of the crystalline phase. In addition, the mechanical properties, especially the plastic deformation ability, of amorphous alloys are closely related to topological morphology of the samples, such as aspect ratio. For the amorphous alloy composite, the relationship between mechanical properties and topological morphology of the samples are of interest. In this work, by adjusting preparation process and size of the samples, the effect of cooling rates and aspect ratios on the mechanical properties of Ti_45.7Zr₃₃Ni_2.9Cu_5.9Be_12.5 amorphous alloy composites were systematically studied. As decreasing the cooling rate during the preparation process, the sizes of dendrites in the amorphous alloy composites increases. And the crystalline phase presents evolution from branchlets to coarse dendrite. As the cooling rate decreases, strength of the composite decreases while plasticity increases. Moreover, different from the previous reports, the mechanical properties of amorphous alloy composite are not sensitive to the aspect ratio. It is attributed to the existing of the dendrites phase and deformation-induced phase transformation in the dendrites, which may adjust stress distribution of the amorphous alloy composites during deformation process.