The effects of adding both yeast culture (YC) and disodium fumarate to diets on ruminal fermentation and bacteria amounts in dairy goats suffered from subacute rumen acidosis (SARA) were investigated. Six lactating goats with permanent ruminal cannulas were induced SARA by gradually increasing feeding concentrate. The experimental animals were fed the combined additives when animals were in SARA period. The ruminal fermentation parameters were determined and the bactaria amounts were quantitated by the traditional rolltube technique and 16S rRNA oligonecleotoide probes hybridization. After feeding the both additives，the pH，acetate，butyrate and total volatile fatty acid concentrations increased significantly (P<0.05), while propionate concentration and acetate/propionate ratio were not affected (P>0.05). The NH₃-N concentration decreased significantly (P<0.05). The populations of amylolytic bacteria， S.ruminantium， M.elsdeni and the three kinds of predominant cellulose decomposing bacteria increased significantly (P<0.05), while those of  Lactobacillus  and  S.bovis  decreased significantly ( P<0.05). It was concluded that adding both YC and disodium fumarate to diets of the dairy goats during induced SARA period could improve rumen internal environment and fermentation, which resulted in decreasing occurrence of SARA.