To determine the optimum fermentation condition, the 50:50 feed mixture of both crushed corn and wet brewer's grain were anaerobically fermented at various conditions. Three supplementation levels(0, 2 %, and 5 %) of molasses, five supplementation levels(0, 0.1%, 0.5%, 1.0%, and 2.0%) of yeast and five different incubation temperatures(4 , ℃ 10 , 30 ℃ , 40 ℃ and 50 ℃ ) were tested to determine the optimum fermentation conditions. During fermenta ℃ tion, alcohol concentration, live yeast cell number (LYCN) and pH values of the mixture were analyzed. Alcohol concentrations of the fermented feed mixtures were proportionally increased with increasing level of molasses supplementation. After 24 hr fermentation, alcohol concentrations at 0.1 %, 0.5 %, 1.0 % and 2.0 % of yeast supplementation was 1.9 %, 2.4 %, 3.1 % and 3.1 %, respectively. These results indicate a proportional increase of alcohol concentration with the increasing supplementation of yeast (P < 0.05) up to 1 %, thereafter showing plateau at 2 % supplementation. LYCN was relatively high with more than 0.5 % yeast supplementation, whereas the value was significantly low(P < 0.05) at 0.1 % yeast supplementation. Alcohol production was significantly higher at 30 and 40 ℃ than other incubation temperatures (P ℃ < 0.05), with the highest concentration at 30 . ℃ pH was rapidly decreased until 24 hours of incubation with steeper decrease at lower temperatures(P < 0.05). Based on there results, optimum fermentation conditions for the alcoholic-fermented feed production could be achieved with 5 % supplementation of molasses, 1 % supplementation of yeast, and 24 hr long incubation at 30 . ℃