Presented in this paper are two main aspects of cotton fiber friction: (1) the role of friction in processing and quality of fibrous assemblies, (2) the fundamental nature of friction. The first aspect emphasizes the critical importance of cotton fiber friction in textile processing and in determining the mechanical behavior of both yarn and fabric. Effects of structural, physical parameters, and surface parameters on cotton friction are also discussed. The fundamental nature of cotton fiber friction and its departure from the Amontonal Laws are discussed on the basis of a structural model developed by one of the present authors (YE).