In order to study the development of ancient harnesses in China and their techniques of manufacture, multi-layer organic residues attached to the back of the bronze buckle in a harness (dated as coming from the Southern and Northern Dynasties to the early Tang Dynasty) unearthed from Shangmiao site in Xunyi County were detected using infrared spectrometry and scanning electron microscopy. The results show that 1) the black residue is animal leather which has been seriously aged, making it impossible to judge the species of animal and the tanning process; 2) the residual textile in the lower layer is made of hemp fiber in a plain weave, with a significant difference between warp and weft lines and a low weaving density. Both form the harness ties jointly. The study found for the first time that the manufacturing process of textile wrapping leather was used for the connectors of various bronze parts on the harness, demonstrating that, at that time, the development of the harness had become preliminarily mature and people fully recognized the characteristics and advantages of hemp products and animal leather as harness connectors and could combine the two.