This study sought to determine the best variety and zone of cotton plantation in 6 places of Region San Martin with the object to recommend its cultivation with Agroindustrial purposes. Above all firstly were evaluated its physical -mechanic properties of cotton fiber (Gossypium sp ) taking samples of varieties Aspero blanco, Une "01", Une "40", and Upland BJA - 594 from following places: Saposoa, San Martin, Juanjui, Picota, Bellavista and Dorado. The physical -mechanic analysis gave as a result that fiber of variety Upland- 594 has most length (29.07 mm - juanjui), most resistance (29.13 g./tex - San Martin) , most fine (4.13 μ - Saposoa). Wlth regard to the elasticity this variety (Upland BJA - 594) had minor about, being reported the raisest ir. province Juanjui with 6.13%. The fibre that presented the best elasticity found in variety Une "01 n from Bellavista (7.77%) which don't qu...