Abstract: Wool weak-link affects the wool quality and its end-use value.However,the evaluation of wool weak_link was only qualitative and indirect because of its indistinct definition.Therefore,this paper makes a clear expounding of the definition,expression and way of measurement of wool weak-links.The key to confirm the causes of weak-links is to express correctly the morphology,structure and tensile behavior of wool weak_links from theoretical and practical aspects.The unique and effective method to characterize the weak-link is to adopt a combined analysis of the properties and morphology of the same fiber.The new approach can be used as an important criterion in the objective evaluation of wool quality,and it can be also applied to other fibers.