Abstract:In this research， production of probiotic pleasant orange juice through its fermentation by lactic acid bacteria （Lactobacillus paracasei） was examined. Fermentation was carried out at 36 ℃ for 10 d under mi－ croaerophilic conditions. Viability counts， pH， total soluble solid and the main antioxidant components were measured in the before and after fermentation. The result indicated that viability counts increased to（7.2±0.30） log CFU/mL from （5.6 ± 0.20） log CFU/mL after 10 d of fermentation， pH and total soluble solid were signifi－ cantly reduced （p＜0.05）， and total phenol content increased significantly （p＜0.05）， total carotenoid and four major flavonoids were significantly reduced （p＜0.05）. The reduction of flavonoids from large to small in order: hesperidin>naringin>poncirin>neohesperidin. There was no significant effect on the indicators for 10 d of storage at room temperature， and the number of viable cells remained at a relatively high level. Therefore， pleasant or－ ange juice was proved to be a suitable media for production of a femented probiotic drink.