Different aspects relative to genetic improvement of Cashmere fibre production are discussed. The world situation of animals' fibres is described together with a description of Cashmere production. Characteristics of the physiology and metrology of fibre are also presented. In addition, genetic variability associated to traits of interest as well as genetic correlations among them are presented. Three selection objectives are discussed taking into account the price of fibre in the international market. Finally, some selection criteria based on restricted BLUP and selection strategies through the use of lineal programming techniques applied to Spanish Cashmere are outlined.