During 2015 and 2016 seasons clusters of Flame seedless grapevines grown under Luxor region conditions were subjected to Ethrel and/or Proton (10% ABA) each at 250 to 500 ppm with or without the application of acetic acid and phosphoric acid each at 2000 ppm. The merit was examining the effect of these materials on advancing maturation of berries and enhancing colouration and quality of the berries.   Treating the clusters with Ethrel and/or Proton (10% ABA) each at 250 to 500 ppm with or without the application of acetic acid and phosphoric acid was very effective in advancing maturation of the berries and enhancing berries colouration and chemical quality of the berries relative to the control treatment. Using Ethrel was superior than using Proton on advancing maturation and enhancing chemical quality of the berries. Moreover, using Ethrel plus Proton was favourable than using each alone in this respect. The best treatment was exposing the clusters of Flame seedless grapevines to Ethrel and Proton (10% ABA) each at 250 ppm plus application of phosphoric acid at 2000 ppm once at veraison stage.