Yam mechanical properties are important for prediction of fabric mechanical behavior and estimation of yam complex quality. The majority of models for yam prediction are based on the fiber characteristics only. These models are valid for restricted range of fibers and yams. In this contribution, the prediction of one-component cotton yam strength, based on the knowledge of fibrous bundles strength (HVI) and correction factors for fibers orientation and yam packing density, is described. This model is compared with models of Neckar [1], Solovev (described in [1]) and Pan [3], [4], [5].