The hypothesis that foliar application of the bioregulator salicylic add(SA)could increase cotton productivity under the environmental conditions of Upper Egypt was tested at the Experimental Farm of Mallawi Agric. Res. Station, Minia governorate, during 2005 and 2006 seasons. Cotton plants of Giza 83 cultivar were sprayed with SA at the concentrations of 0,50,100 , 200 , 300 , 400 and 500 ppm at early flowering stage. Results of this study showed that , in comparison with the control , the lower SA concentrations up to 200 ppm significantly increased leaves content of chlorophyll a and total chlorophyll, while all SA treatments increased leaves content of polyphenols and total phenols . However, leaves content of chlorophyll b or sugars was not significantly affected by SA application. The application of 100-200 ppm SA significantly increased open bolls per plant and seed cotton yield per fad. in both 'seasons as well as boll weight only in 2005 season , but significantly decreased nonopen bolls per plant in both seasons . The same trends of these traits were obtained by 50 ppm only in 2005 season . The concentration of 300 ppm significantly increased number of open bolls per plant in 2006 season and significantly decreased number of nonopen bolls per plant in both seasons . The higher SA concentrations , 400 and 500 ppm, gave almost no significant effects on yield and its components. SA application had no significant effects on plant growth characters , earliness % , lint % , seed index and fiber quality in both seasons. The highest seed cotton yield and the best responses in general were obtained by 200 ppm in 2005 season and 100 ppm is 2006 season . Therefore , it could be concluded from results of this study , that SA could be used at the concentration of 100 or 200 ppm to improve cotton productivity under the environmental conditions of Upper Egypt.