This experiment was achieved out during 2015 and 2016 seasons on 15 years old "Thompson seedless" grapevine grown in loamy clay soil under flood irrigation system at a private farm in Gharbia government, Egypt. The vines were planted 1.5 meter in row and 3 meters between rows. The vines were cane trained with three wires trellis supporting system. Five treatments; calcium nitrate at 1%, potassium sulfate at 2.5%, Sitofex (CPPU) at 6 mg/ L and Moringa leaves extract (MLE) at 2.5% and 3.5% were used as a spray application either single or in combinations on the vines at two times (at 20 cm of shoot length, and 4 mm of berry diameter). The results appeared that single applications of Ca at 1%, K at 2.5%, CPPU at 6 mg/ L as well as MLE at 2.5 and 3.5% or in combination of them were effective in improving the quality and total yield per feddan. The application of potassium sulfate at 2.5% + CPPU at 6 mg/ L as well as potassium sulfate at 2.5% + MLE at 3.5% were the superior treatments since they reached the best berry characters (berry firmness, berry diameter, weight and volume of 100 berries), cluster parameters (cluster weight, cluster length and cluster width), berry juice quality (total soluble solids (TSS%), acidity (%)  and TSS/ Acid ratio) and yield per feddan as compared to control in both seasons. This suggested that Moringa leaves extract could be used as an alternative treatment for enhancing yield and quality of "Thompson seedless" grapevine.