Two application methods of Indol Acetic Acid (IAA), soaking seeds and spraying plants at the beginning of flowering, were employed with two concentrations (25 and 50 ppm) plus non-treated check (water) on two planting dates (25 March and 25 April) of cotton in 2003 and 2004 seasons at Sal is Agricultural Research Station. Giza B8 cultivar was used Soaking seeds in solution of MA was done for 12 hours before sowing. The data revealed that sowing cotton in 256' March had significantly decreased final plant height, while number of main stem intemodes, number of sympodia per plant, nodal position of the first sympodium, days to first flowers and first open boll, earliness percentage, number of open bolls per plant, boll weight, seed cotton yield per plant and per feddan, seed index and fiber fineness were increased. Comparing with untreated plants with MA, the obtained results showed that the application of MA, in general, increased all studied characters except nodal position of the first sympodium and fiber properties, which were not significantly affected. The best results were obtained by soaking seeds 12 hours before sowing in a solution of 25 ppm Indol Acetic Acid. The application of IAA either soaking seeds or spraying plants increased seed contents (oil and protein %) and total dilorophyll in leaves, especially when applied at low concentration (25 ppm) compared with untreated plants. Soaking seeds before sowing in 25 ppm of solution IAA gave the highest values of oil %, protein % in seeds, total chlorophyll in leaves, reducing sugars, non-reducing sugars, soluble sugar and phenols, while carotenoides were decreased. The interaction between planting date 'and MA treatments had significant effect on final plant height, number of open bolls per plant, boll weight and seed cotton yield per feddan in 2003 season. Generally, it could be conduded that Indol Acetic Add (IAA) gave the highest yield, yield components and seed quality characters when it was applied at early sowing date by soaking