Six endophytic fungal species belonging to genera, Aspergillus, Alternaria, Penicillium, and Fusarium, as identified morphologically, were isolated from healthy leaves, stems, and roots of the medical plant Euphorbia peplis collected from Damietta governorate of Egypt. One Fungal strain morphologically identified as A. oryzae, was selected as the most potent producer of Kojic acid, that produced in this study by agricultural waste fermentation using sugarcane bagasse, corn cobs, and rice straw. The bagasse agricultural waste fermentation using endophytic Aspergillus oryzae strain was optimized as a source of Kojic acid in a cheap, fast, and environmentally beneficial way at agitation state rather than static and pH 6.0 after 20 days of incubation at 28 °C. Ethyl acetate extract of filtrate of  Aspergillus oryzae showed promising antioxidant activity against DPPH free radical, recording IC50 = 5.7. Also, the E A extract was separated using Gas Chromatography technique recording RT: 31.95 min. and MW: 142.The study aims to the fermentation biotechnology used to reduce the cost of industrial KA production through optimization of environmental conditions of the biosynthesized KA with low toxicity and high antioxidant efficiency