Abstract: Durian fruit waste (peel and seed) can be used as an alternative feed based on the potential availability and nutrient content. Three experiments were conducted to improve the nutrient quality of durian fruit waste (DW) and tofu waste (TW) mixture through fermentation by using Phanerochaete chrysosporium and Neurospora crassa. The substrates consists of 70% DW (peel and seed in the same proportion) and 30% TW. Experiment 1 was performed in a 3 x 3 factorial experiment of completely randomized design with 3 replicates. First factor was inoculum composition of P. chrysosporium and N. crassa (1: 1, 2: 1 and 1: 2) and second factor was inoculums doses (6, 8 and 10%). Measured variables were Crude Fiber (CF) and Crude Protein (CP). Experiment 2 was to study incubation period (7, 9, 11 and 13 days). Measured variables were DTW’s CF, CP, cellulose, hemi-cellulose and lignin. Experiment 3 was to compare nutrient content between fermented (the best treatment at experiment 2) vs. unfermented one. Measured variables were DTW’s nitrogen retention, amino acid profile, B carotene, tannin and Metabolizable Energy (ME). Result of the experiment 1, there was a very significant (p<0.01) interaction between inoculum compositions and inoculum doses in which P. chrysosporium and N. crassa inoculum composition (1:1) and 8% inoculum dose reduced CF and increased CP content. Experiment 2, incubation period of 9 days reduced CF, NDF, ADF, lignin and cellulose from 22.33, 32.49, 27.50, 15.81 and 17.62 to 8.30, 30.58, 20.26, 6.20 and 11.58%, respectively. Meanwhile increased CP and hemicellulose from 11.73 and 4.99 to 19.37 and 9.52%, respectively. Experiment 3, Nitrogen retention, B-carotene, tannin and ME content of fermented was better than unfermented DTW (42.50 vs 68.54%, 0 vs. 119.07 mg/kg, 3,76 vs 0.43% and 2586.84. vs. 2728.27 kkal/kg, respectively). Phanerochaete chrysosporium and Neurospora crassa treatment improved DTW’s amino acids profile. In conclusion, fermentation by using Phanerochaete chrysosporium and Neurospora crassa (1:1), 8% inoculum dose and 9 day incubation period was the best treatment for improving DTW’s nutrient quality.