Fermented beverage can be made from whey goat cheese base ingredients with Lactobacillus casei as inoculum. This product weakness is the aroma and viscosity that consumers have not liked. The addition of mango juice and carboxymethyl cellulose (CMC) is expected to improve product quality. This study aimed to explore the effect of mango juice and CMC concentrations on product quality. This research used complete randomized design with 2 factors. The analysis included physical, chemical, microbiological and sensory analysis of hedonic test. The results showed that mango juice concentrations significantly affected color and attributes of color, taste, and viscosity while CMC concentrations significantly influenced viscosity, color, and sensory attributes of color, aroma, taste, and viscosity acceptability. Mango juice and CMC concentration did not effect on pH, lactic acid, total soluble solids, protein, L. casei, taste and overall sensory attributes. The average sensory value of panelists indicated a slightly dislike to this product.