This study was conducted to determine the effect of additive teatment on microbial succession and fermentation characteristics during d 8 (0,2,4,8) of ensilimng period of com for silage and changes of nutrients contents, fermentation products and in vitro digestibbility of dry matter were investigated after d 45 of ensiling. Corn tor silage treated with addivite was divided into groups. These group. These groups were control group (K) no addivıte. AİV group (AİV) with %8 AİV solution, formic acid group (F) with %5 formic acid and HCIgroup with %5 HCI (H). The fermentation products, e.g., lactic, acetic acid and ammonia-N increased, but counts of mold and aerob bacteria decreased as ensiling time advanced. This increasing or decreasing was lower in treatment group than control group. Lactic, acetic acid and ammonia-N concentrations were lowered by addition acids, but counts of toial aerob bacteria and mold were hgher in control group than in treatment gdoups in silage (p<0.01), Dry matter, ash. ether extract contents of silage were not different (p>0.05) between groups, but organic matter, crude protein, nitrogen free extract were higher than control group (P<0.05). Crude fiber content was lowered by addition acids (p<0.05). The in vitro digestibility of dry matter in silage were 61,76, 64,83, 66.34 and 65,21% in K, AİV, F ve H groups, respectively (p<0.05).