Chinese gold and sliver gilded bronze harnesses dated at Western Han Dynasty (221 B.C-8 A.D.) were studied by the metallurgical microscope, X-ray fluorescence (XRF), X-ray diffraction (XRD), and Environmental scanning electron microscopy (ESEM). Metallurgical microscopy and ESEM have shown that a sub-layer of gold gilded should be prepared on the leaded bronze surface before the silver gilded layer was applied. Metallic compounds of Ag0.36Au0.52Hg0.09Cu0.2, (Ag, Au)Hg, (Ag, Au)3Hg2, and Au3Hg were detected by XRD. This research gives the evidence that mercury silvering and mercury gold gilding were used in the Western Han Dynasty.