The field experiment was carried out during 2020/ 2021 and 2021/2022 seasons on Washington Navel orange and grown in a private citrus orchard located at Wady Al-Mollak, district Al-Ismailia Governorate, Egypt. Used complete block randomized design with three replicates. Thirteen treatments were applied as a combination between amount of bio fertilizer (3, 4, 5 L) and four levels of mineral nitrogen (100, 90, 80, 70 kgN/fed) as well as control (0 L. Bio 100 kgN/fed). The results showed that significant between treatments for all studies characters. The treatment 5 L. Bio. + 100 kgN/fed, given the highest values of number of flowers, fruit set%, tree yield/kg and fruit yield/fed (ton). Also, this treatment improved fruit chemical properties. It can be concluded that 5 L. Bio. + 100 kgN/fed enhancement total number of flowers, fruit set percentage, yield/tree and fed. as well as fruit chemical characters.