The structural evolutions of Lanthanide-based metallic glasses under high pressure annealing were investigated by using X-ray diffraction, differential scanning calorimetry, in situ high pressure angle dispersive X-ray diffraction measurements with synchrotron radiation, and nanoindentation. The results show that the amorphous structure in the glasses keeps quite stable up to approximately 40 GPa at room temperature. The high pressure annealing treatments reveal that pressure can inhibit the crystallization process, improve local packing efficiency, and restrain long-range atom diffusion. The thermal stability and hardness of the alloys both improved after the treatment. The approach has implications for the design of the microstructure-and property-controllable functional materials for various applications. (C) 2012 Elsevier B. V. All rights reserved.