The present investigation was carried out at the Agriculture Research Station, Faculty of Agriculture, Alexandria University in the summer seasons of 2005 and 2006, to investigate the influence of three sowing dates (April 10^th, May 1^st and May 20^th) on seed yield and quality characters of six soybean cultivars, i.e., Crawford, Clark, Giza 21, Giza 35, Giza 111 and Giza 22. Delaying sowing reduced seed yield/ ha of 12 kg/ ha by each day delay in sowing after April 10^th. Seed protein and oil contents also decreased with delaying sowing beyond May 1^st. Fatty acids composition was altered with delaying sowing where oleic and linoleic acid contents increased while that of linolenic acid decreased. Variability between soybean cultivars was observed for seed yield and all quality characters. Cultivar Giza 111 produced the highest seed yield/ ha, but was low in protein and oil contents, and intermediate in oleic and linoleic acid contents. Significant sowing date ´ cultivar interaction was found for seed yield/ ha, oil content, total soluble fatty acids (T.S.F.A), linoleic and lionlenic acid contents. Also, a cultivar ´ season interaction was detected for seed yield/ plant, seed oil content, T.S.F.A, oleic and linoleic acid contents, indicating the environmental conditions influence on these characters.