A study is presented regarding the relationship between cotton fiber and field properties and three responses: cotton yield yarn, strength and yarn appearance. Fiber properties such as upper half mean length, length uniformity, strength and micronaire fineness, and other characteristics such as percent lint, weight of one boll and weigth of 100 seeds are studied in relation to cotton yield, yarn strength and yarn appearance. Statiscal models were developed through multiple regression analyses to show the degree of relationship between three responses (cotton yield, yarn strength and appearance) and seven independent variables. Multiple regression analyses were carried out to determine the order of importance of each independent variable in relation to a specific response. The 57 cotton strains and varieties used in this study were obtained from 9 locations troughout the State of São Paulo, in a total of 801 samples.