This investigation was carried out during two successive seasons (2019 & 2020), to study effect of some natural sources for Anti-stress compounds namely: Chitosan at (100 ppm), Ascorbic acid at (100 ppm), Prolin at (30 ppm) and Vitamin E at (50 ppm) as foliar applications on Washington Navel orange trees for elucidating their effects on tree vegetative growth & physiological performance, initial fruit set & retention and yield & fruit quality which grown Ehnasia restrict / "Beni- Suief"  Governorate conditions. Experimental treatments were spraying  at three times at the 1st weeks of : May, July & September for two seasons. Results indicated that, all the natural sources for Anti-stress compounds positively improved Washington navel orange tree (growth & physiological performance, initial fruit set & retention and yield as :a number & weight & fruit quality. Whereas, Chitosan compound has a superior effect with significant difference on the above parameters, when compared to other treatments under this study for both seasons. Moreover, anti-stresses compounds under study could be arranged Chitosan, Ascorbic acid, Prolin and Vitamin E respect., as for their effetivness.