This research was in 2014 and 2015 seasons on Picual and Kalamata olive cultivars. Trees were about 15 years old, planted at 6×4 meters apart in a sandy soil, under drip irrigation system at privet orchard located at Cairo –Alexandria desert road. The research aimed to study the independent effects of foliar application with Mono ammonium phosphate, Mono potassium phosphate and Urea phosphate at the rate of 1% on flowering, fruit set, yield, oil content and fruit characteristics of Picual and Kalamata olive trees. Results revealed positive effects for improving flowering, fruit set, yield, fruit characters, and fruit oil content, also reduced the number of dropped fruits. The most effective treatment by spraying Mono potassium phosphate (twice), first in the mid of January and repeated in the mid of May that help to compensate the depletion of mineral nutrient and enhancing tree yield and fruit characters of Picual and Kalamata cultivars.