Under high-energy ball milling, elemental powder mixtures with a nominal composition of Ti50Cu20Ni24Si4B2 can be amorphized via solid state reaction. A well-defined glass transition before crystallization appears in the obtained amorphous phase during heating in a differential scanning calorimeter. A wide supercooled liquid region, AT, is detected being about 57 K. Crystallization of the ball-milled amorphous phase was performed through one step to form the metastable (Ni, Cu)Ti phase with cubic structure and an unknown phase, which is a eutectic-type transition, followed by subsequent grain growth. The reduced glass transition temperature of the alloy was determined to be 0.56.