Abstract: Although new cables are covered by smooth polyethylene material, weathering and dust adhesion increase the surface roughness of the cables with the growth of service time. In this paper, the influence of roughness of stay cables on aerodynamic stability was studied. The surface roughness of cables was changed through covering the cable with different sandpapers, and the surface roughness was measured with the SJ-410 high-precision by free vibration wind tunnel test. The influence of surface roughness on the vibration of stay cables at high Reynolds number was studied by vibration experiments. It was shown that the vibration of stay cables was inhibited with the increase of the surface roughness; the Reynolds number effect became weaker with the increase of surface roughness of the stay cable models.