This investigation carried out during the two consecutive seasons 2016/ 17 on mango trees (Mangifera indica L.) cvs,''Haydi and Naomi''. The trees were grown in a private orchard at El Salhia region Sharqia in a sandy soil and Irrigated with drip irrigation system. Trees Were five Year-old Tree planted at 2x5m space to evaluate the effect of foliar biostimulator at ( 0, 0.4, 0.6 and 0.8mg/L) at full bloom and again at30 days later on yield and fruit quality. Results showed concentrations of stimulant increased the yield / tree (Kg) or number of fruits/ tree especially 0.8mg/L concentration. As well as, Fruit physical i.e. weight, volume, length, width, thickness, firmness and peel weight, stone weight, pulp weight characteristics fruit specific gravity and net ratio percentage were increased by this treatment. So, using the Stimulant as a foliar spray on mango trees at 0.8mg/L may improve fruit quality and increase yield of the trees. Conclusively, results of the present work, generally, make possible to recommend producing high yield of mango fruit characterized by good physical properties by foliar application of growth stimulant.