We performed high-temperature microcompression tests on micron-sized pillar samples fabricated from Au49Ag5.5Pd2.3Cu26.9Si16.3 metallic glass near the glass transition temperature to investigate the homogeneous deformation behavior. Samples were invariably deformed uniformly. The strength was observed to decrease with increasing temperature and decreasing strain rate. Plastic flow behavior can be described by a shear transition zone model. The activation energy and the size of the basic flow unit were both deduced and compared favorably with the theory.