Two field experiments were carried out at Gemmiza Research Sta­tion. during 1996 and 1997 seasons to study the effect of Ascobine compound and ascorbic acid on cotton plants cv. Giza 75. Ascobine (containing 25% ascorbic acid and 13% citric acid) at two rates, 200 and 400 g per feddan, and ascorbic acid at three rates of 200, 300 and 400 ppm were sprayed on cotton plants either once at start of flower­ing or twice i.e., at start and at peak of flowering. The obtained results showed that one spray of ascobine or ascor­bic acid increased plant height significantly. One spray of ascobine at a rate of 400 g/fed. and two sprays of Ascorbic acid at a rate of 200 ppm tended to increase the number of fruiting branches per plant significatly. Spraying ascobine or ascorbic acid seemed to increase number of open bolls per plant, as a result of reducing boll shedding. In cotton leaves, all chlorophyll forms.i.e., chlorophyll a, b and total chlorophyll increased sig­nificantly by spraying these compounds either once or twice. The hgih­•est levels of reducing sugars and total soluble sugars were observed when 300 ppm ascorbic acid was sprayed at start of flowering. One or two sprays did not affect boll weight, however 200 g/led. ascobine pro­duced the highet value of boll weight. Number of sprays did not affect lint percentage, earliness of yield (except for ascorbic acid at 200 ppm in 1996), and seed cotton yield. Various concentration of ascobine and ascorbic acid affected fiber properties insigificantly. Oil seed conent was increased significantly.