This experiment was conducted in two successive seasons (2018, 2019) on Coratina olive trees planted in a private orchard located at El Khatatbah district, El Behera governorate, Egypt; to study the effect of potassium dihydrogen phosphate (KH2PO4), magnesium sulphate (MgSO4) and boric acid (H3BO3) on olive yield per tree, fruit quality, also content and characteristics of fruit oil. The treatments were applied twice in September and November of each season. Generally, using any of the treatments under this investigation is led to increase the fruit yield per trees, and the fruit physical characteristics, also the oil accumulation percentage in the fruits, with maintaining its characteristics and quality as extra-virgin olive oil, compared to the untreated trees (control). However, treating the trees with magnesium sulphate alone recorded the highest fruit yield in the first season compared to the control. While, treating trees with potassium dihydrogen phosphate + boric acid + magnesium sulphate treatment, led to the highest oil percentage in the fruits, in the second season.