Zr50Al15Ni10Cu25 amorphous powder was synthesized by mechanical alloying. The effect of Si3N4 addition on the crystallization behavior of the alloy during sintering process was studied. Thermal stability of the powders was performed by differential scanning calorimetry (DSC). The phase and microstructure of the powders and bulk specimens sintered were determined by X-ray difrractometry (XRD) and scanning electron microscopy (SEM). The results show that, introducing 0.05% (mass fraction) Si3N4 can enhance the crystallization activation energy of the Zr50Al15Ni10Cu25 amorphous powders, which indicates that Si3N4 addition has hindrance effect on forming crystals from Zr50Al15Ni10Cu25 amorphous powder. However, 0.10% Si3N4 results in the decrease of the crystallization activation energy, which makes its crystallization process easy to occur.