Two field experiment were carried out during 1988 and 1989 seasons at Sids Agricultural Research station. Beni-Suef Governorate to study the effect of planting dates. N levels, and P fertilization on yield and yield components of Giza 80 cotton cultivar. The results could be summarized as follows: The total number of fruiting branches, number of boils/plant, number of opcncd boils/plant, boll weight and seed colon yield significantly increased b planting, Whereas. first picking percentage significantly increased by cladding sowing date. increasing N level co 60 kg/fed significantly increased number of fruiting branches/plant, and seed cotton yield/plant, Also, number of boils and number of opened boils/plant and seed cotton yield (kentar/fed.) were increased with the increase in N levels to 90 kg/fed. P fertilization resulted in an increase in number of boils! plant. number of opened bulls/plant and seed cotton yield. The interaction effects between sowing dates, N levels, and P fertilization were significant on most of the studied traits in both seasons.