This study was carried out during the seasons of 2014, 2015 on Washington navel orange (Citrus sinensis L. Osbeck) cultivated in a commercial orchard located in Shiwah Valley near Aga city, Dakahleia Governorate, Egypt. to study the effect of organic fertilization such as humic and Fulvic acid as a soil application on fruit set, dropping and yield of Washington navel orange . The data reveal that adding humic or fulvic acid each alone or together significantly increased the fruit set percentage but reduced pre-harvest drop than the control. The data also, showed that adding humic acid at 30 ml with fulvic acid at 100 ml significantly increased the number of fruit per trees than the other treatments or the control since, this treatment gave a higher yield. Whereas no clear effect had obtained on average fruit weight. Furthermore, both humic or fulvic acid applications gave no clear effect on average fruit juice than the control. So, this treatment gave no clear effect on SSC, total acidity and SSC/acid ratio in fruit juice than the control. but ,thes treatment gave a somewhat increment on average Vit-c in fruit juice.