Abstract: Two experiments were conducted to improve Juice Wastes Mixture’s (JWM’s) nutrient quality by using Trichoderma viride and to compare between treated vs. untreated one. This JWM consists of carrot, apple, mango, avocado, orange, melon and tree-tomato in the same proportion. Experiment 1 was performed in a 3 x 5 factorial experiment of completely randomized design with 3 replicates. First factor was Trichoderma viride concentration (5, 7 and 9%) and second factor was incubation period (0, 5, 7, 9 and 11 days). Measured variables were Crude Fiber (CF), Crude Protein (CP) and Ether Extract (EE). Experiment 2 was to compare nutrient content between treated vs. untreated one. Measured variables were JWM’s CF, CP, EE, NDF, ADF, cellulose, hemi-cellulose, lignin, nitrogen retention, amino acid profile and Metabolizable Energy (ME). There was a very significant (p<0.01) interaction between Trichoderma viride concentration and incubation period in which 7% Trichoderma viride and 5 day incubation period reduced CF and EE and increased CP content. CF, EE, NDF, ADF, cellulose, hemicelluloses and lignin contents between untreated vs. treated one declined from 17.10, 6.24, 34.30, 24.40, 12.20, 9.90 and 11.80% to 12.23, 3.72, 31.55, 22.43, 11.15, 9.12 and 11.28%, respectively. Meanwhile, nitrogen retention and CP increased from 58.40 and 8.40% to 63.64 and 11.29%, respectively. ME content of treated was better than untreated JWM (1774 vs. 2599 kkal/kg). Trichoderma viride treatment improved JWM’s amino acids profile. In conclusion, fermentation by 7% Trichoderma viride at 5 day incubation period was the best treatment for improving JWM’s nutrient quality.