The objectives of this study were to determine the effect of inoculant, enzymes and inoculant-enzymes mixture on fermentation quality, nutritive value, and microbial changes of sorghum straw silage. Sorghum straws were collected and treated with distilled water (control), inoculant, enzymes and inoculant + enzymes prior to ensiling. Three bag silos for each silage (denoted C, I, E and I + E, respectively) were opened after 3, 7, 11, 15, 30 and 60 days for chemical and microbial analyses. For all the silages, there was a rapid decline in PH during the first 3 days of ensiling. Relative to silage C, all the treatment (I, E and I + E) had higher (P < 0.05) lactic acid concentration at all ensiling periods. Population of LAB during all ensiling time was numerically greater for treated than control silages. Separate addition of two additives, especially for enzymes, can effectively (P < 0.05) decrease aNDF and ADF concentration. Treatments with enzymes (E, I + E) can also improve significantly silage IVDMD and IVNDFD concentration. These results indicated that the addition of additives can improve the sorghum straw silage fermentation quality at different extent. (C) 2008 Elsevier Ltd. All rights reserved.