Abstract: Friction hollow yarns are produced by removing the water soluble PVA yarns in the boiling water from the core friction yarns which are spun by using PVA yarns as the core and cotton fibers as the sheath.The structural features and the tensile properties of friction hollow yarns are examined.The main structural feature of the friction hollow yarn is that the yarn has a hole in the yarn center.The structure of the yarn after boiling becomes looser,and the yarn diameter is increased.The experimental results show that the strength of the friction hollow yarn is very low.It is due to that high strength core filaments have been extracted and inter-fiber cohesive force is diminished after the friction yarn is boiled.The strength of the friction hollow yarn can be increased obviously by using polyester multi-filament yarn as core enforcement.