The effect of N and P on seedcotton yield boll andfiber properties of three Cultivars were studied during 1984 and 1985 seaso The results showed that N is an important factor affecting seedcotton yield/fad., number of open boils/plant1 boil weight and length parameters. P applied had a signifjca effect on seedcotton yield and its macrocomp(,nents given above. Differences among cultivars were signifjca for number of open boils/plant, boll weight lint percent, staple length, fiber finesa and strength. Fiber properties were not affected by applied P in the three studied cultivera. A signifjca cultivar x N interaction was detected for seedcotton yield/fad. for all cultjvars. And significant N x P x cultivar inter action was detected for the number of boll/plant.