This study made use of WATOS fiber and WATOS fiber blended yam. WATOS fiber is made by spinning. During the spinning process of polyester fiber, Chinese herb with natural antibacterial function would be added into it. WATOS fiber yarn is made by blending WATOS fiber and cotton at the ratio of 50:50. Throughout this article, the surface morphology, infrared spectroscopy and mechanical properties of WATOS fiber will be studied and analyzed. The mechanical properties of WATOS fiber, including breaking tenacity and elongation, will be compared with polyester fiber. What's more, the mechanical properties, hairiness, moisture regain, acid and alkali resistance of WATOS fiber blended yarn will be characterized.