The objective of this study was to evaluate the effects of commercial acid mixtures on silage chemical composition, lactobacillus, yeast and mold in the silages and organic matter digestibility. The treatment groups as follows: (1) Control (C, no additive), (2) formic acid, propionic acid and lignosulphopic acid mixture (1 g/kg, SA, soft acid (R)), (3) calcium formiate, sodium benzoate and sodium metabisulfite mixture (1 g/kg, Silamix (R)) and (4) SA+SM mixture (1 g/kg SA+1 g/kg SM) admixed to fresh sunflower crops. Then, fresh crop materials were filled one kg in vacuum nylons and vacuumed with six replicates and kept for 90 days at room temperature (about 20 to 26 degrees C). Dry matter content of silages were lower in the SA+SM supplemented group than those of C and SA groups and crude protein content of SM and the SA+SM groups lower than those of C and SA groups (P<0.01). The crude fiber and acid detergent fiber ratio were higher in the C group than the other groups (P<0.01). In the C group the HEM content were lower than SA+SM group (P<0.05) and in the SA group's ADL were higher than those of other groups (P<0.01). Acids supplementations increased total digestibility nutrient ratio. The lactic acid concentration in the SA+SM group were higher than those of other groups and in the SM group, organic matter digestibility were higher than those of C and SA groups (P<0.01). Acid addition was not affect pH, ether extract, NDF, and lactobacillus and yeast count of silages. In conclusion, acids mixture supplementation to sunflower silage caused a decrease in DM, CP and ADF content, however, increased HEM, TDN, LA and OMD and so they may improve silage quality.