Abstract: To explore the effects of treatment of corn germ meal by different microbes on the fermentatinn parameters of rumen invitro,high bacteriocin producing lactic acid bacteria,yeast,bacillus subtilis and its combination were processed on corn germmeal, each with 5 replicates;then GP, pH, DMD, NH3-N of the mixed bacteria group with better effect and the raw materials weredetermined. The results showed that ： compared with the control group,CP of each treatment group increased significantly （P〈0.05） ,TP of the mixed bacteria group was significantly increased （P〈0.05）,and NDF of＂ each treatment group decreasedsignificantly （P〈0.05）.GP of 2-48 h in the mixed bacteria group was significantly higher than control group （P〈0.05）.B value（tile smoothness of the gas production cnrve）aud C value （time of the maximum value of theoretical gas production）weresignificantly higher than control group （P〈0.05）. pH of the mixed bacteria group in 48 h was significantly lower than controlgroup （P〈0.05）,DMD and NH3-N in the mixed bacteria group were significantly higher than control group （P〈0.05）. Inconclusion,microbial treatment of corn germ meal can irnprove the nutritional value of the raw material,while effect of mixedbacteria treatment is better. Mixed bacteria treatment can improve the utilization value of corn germ meal by ruminants.