Abstract: To promote the quality and function of yogurt Mesona Benth Jelly (YMBJ), a novel strategy was used by regulating culture components and fermentation conditions. Healthy and tasty YMBJ, with high antioxidant activity, was developed by the addition of Chinese herbal medicine (CHM) during the fermentation of Mesona Benth(MB) using lactic acid bacteria (LAB). The sensory evaluation of YMBJ quality was conducted by 10 sensory assessors in three groups. The sensory evaluation index of the product quality includes four aspects:tissue state (35 points), chewy taste (30 points), fermentation flavor (20 points) and appearance color (5 points). The total score of sensory evaluation is the sum of the scores of the four aspects. The antioxidant activity of YMBJ was evaluated by the antioxidant indexes including DPPH scavenging capacity, reducing power, ferrous ion chelation, and inhibition of linoleic acid peroxidation. The dose-effect relationship between polysaccharide and antioxidant activity was also discussed. Through single factor and orthogonal tests, the optimal performance of YMBJ was determined. The results showed that the optimal performance of YMBJ was achieved when 16% of sugar, 1% of Chinese herbal medicine, 12% of LAB inoculations, and 10 g of MB powder were fermented for 12 h. The YMBJ had a rich flavor, sweet and sour taste, chewy texture and delicious taste. The results of variance analysis and orthogonal test showed that the effect of each factor on sensory score of YMBJ was as follows:the addition of CHM had the greatest impact on the sensory quality of the product, followed by the addition of sugar, and then the addition of bacteria, and the effect of fermentation time was the last. The antioxidant indexes including DPPH scavenging capacity, reducing power, ferrous ion chelation, and inhibition of linoleic acid peroxidation in YMBJ were significantly different at (90.50±3.60)%, (0.93±0.08, A₇₀₀), (73.40±6.50)%, and (57.80±4.80)%, respectively (P< 0.05). The strength of the antioxidant ability was as follows:test group of CHM and LAB addition (EX) > control group of LAB addition only (CL) > control group of CHM addition only (CK) > blank group of MH (BK). The total antioxidant activity of polysaccharide was the sum of LAB exopolysaccharide (CL), Chinese medicine polysaccharide (CK) and MB polysaccharide (BK). According to Fick's law, it is pointed out that there is addition effect when the concentration of polysaccharide is the sum of its total amount, and the antioxidant activity also showed the same phenomenon. It is suggested that Chinese medicine may contain some bioactive factors to stimulate the biochemical reaction of enzyme system in LAB fermentation process and promote the production of polysaccharide. The antioxidant activity increased with the increase of polysaccharide content in a dose-dependent manner, indicating that the addition of CHM could promote the quality and antioxidant activity of the YMBJ. The additive effect of antioxidant activity was due to the total expression by complex polysaccharide of YMBJ through the fermentation, including the polysaccharides of MB, CHM and LAB exopolysaccharide. This research provides a theoretical basis for the study of promoting the antioxidant activity of healthy foods.