Abstract: Cashmere,wool and polyester(PET) fibers were selected to form a three-strand complex yarn on traditional ring spinning system,and obtained yarns of different structure and style by changing feeding location and tension of three components.Three sorts of compound structural yarn were spun with different twists and blended ratios,such as plied,core and wrapped structural yarn,and yarn tensile property was tested.The spinning experiments and test results show that this could improve the strength of cashmere yarn by compositing and there are some relationships between the tensile property and blended ratio,twist and yarn structure.Along with the increasing of twist,tensile property of the three structural compound yarns all accords with classical critical-twist theory.The mechanical property of compound yarn varies with its structure,and in the case of tensile strength,plied structure yarn is the best,followed by core structure yarn,and wrapped structure yarn is the worst.