Abstract: Lint yield per plant and its 3 yield components of 23 upland cotton varieties (lines) over the years 2000-2001 were studied using conditional analysis method. Results indicated that among the 3 component traits that influenced yield per plant directly lint number per plant had the largest contribution, while lint percentage had the smallest contribution. Interaction between other factors besides lint percentage and environment had the largest influence on yield per plant, whereas interaction between other factors besides lint number per plant and environment had the smallest influence upon the object trait. Various cultivars had different genetic effects, 3 component traits of various cultivars had different contribution to yield per plant.