Two field experiments were carried out at Sakha, Agricultural Research Station during 1999 and 2000 seasons to study the response of late sowing cotton cultivars (Giza 88) to three nitrogen levels (30, 45 and 60 kg N/fed) as a main plots and three timing of potassium application 24 kg K₂O/.feddan (before the first irrigation, before the second irrigation and before the third irrigation) plus unfertilized treatment with K as subplots. Combined data revealed that increasing nitrogen fertilizer levels from 30 up to 60 kg N/fed increased final plant height, main stem internodal length, number of sympodia, nodal position of the first sympodium, days to first flower and open boll, earliness percentage and dry weight of vegetative and fruiting organs, while number of main stem internodes and seed cotton yield and its components were not significantly affected by nitrogen fertilizer levels.                 Comparing with unfertilized plants with K, results indicated the positive effect of potassium when it was applied at the proper time as application before the second irrigation which resulted in less number of monopodia and higher number of sympodia, higher dry weight of vegetative and fruiting organs, heavier bolls, higher number of open bolls as well as seed cotton yield per plant and per feddan. Potassium fertilization showed no effect on final plant height, number of main stem, main stem internodal length, node location of the first sympodium, days to first flower, earliness percentage, lint % and seed index.                 The results indicated that increasing nitrogen fertilizer rates from 30 up to 60 kg N/fed. significantly increased plant height, main stem internodal length, number of sympodia/plant and delay in maturation. Moreover, number of open bolls, boll weight, lint percentage and seed index insignificantly affected by nitrogen levels at late sowing.                 The interaction of nitrogen level by K treatments was not significant for all traits studied in this investigation.                 Generally, results obtained revealed that nitrogen fertilizer levels had a little effect on yield of late sowing cotton and the soil application  of potassium fertilizer before the second irrigation is the proper timing to apply this element for maximizing cotton productivity.