Two field experiments were conducted during summer seasons of each 2012 and 2013 in the Ras-Suder Research Station, South Sinai, Desert Research Center. The main object of this research was studying the effect of some antioxidant treatments on morphological growth characters of sweet pepper plant (Capsicum annuum L.) hybrid cultivar "Sonar". Aqueous solutions of antioxidants were used as foliar spray; viz., ascorbic acid (Vitamin C), oxalic acid, salicylic acid and, tocopherol (Vitamin E) within four different concentrations of these antioxidants (0.0, 200, 400 and 600 ppm) were applied at 20, 40 and 60 days after transplanting. Obtained results reflected that the highest values of growth parameters expressed as plant height, number of branches and leaves per plant, fresh and dry weight per plant and leaf area per plant as well as reading total chlorophyll were significantly affected by antioxidants, the highest values were recorded spraying with salicylic acid and ascorbic acid at 400 ppm.