The present study was carried out during the two successive seasons of 2014 and 2015 on eight years old Keitt mango trees, in order to investigate the effect of spraying each of NAA(40ppm), GA 3 (40ppm), CPPU(10 ppm), BA (40ppm), SA (250 ppm) and CaCl 2 (0.75%) after fruit set on fruit drop, yield and fruit quality of Keitt mangoes trees. Trees were spaced at 2 X 3 meters apart and grown in a sandy soil at a private orchard in Edko region, El-Behera governorate, Egypt. Trees were sprayed twice; after fruit set and 30 days later in a randomized complete block design (RCBD). The results showed that the fruit drop percentage after one, two and three months from the application date was significantly decreased and the fruit retention percent and yield per tree were increased by all sprayed substances in comparison with the control in both seasons. Generally, trees spraying with NAA, GA 3 , CPPU or BA was considered the best and effective in decreasing fruit drop and increasing fruit retention and tree yield. Spraying GA 3 , SA and CPPU improved some fruit physical characteristics in comparison with the control. In the meantime, spraying SA, NAA and CaCl 2 had positive influence on fruit chemical characters in comparison with the control.