The effects of adding disodium fumarate and monensin to diets on rumen fermentation and bacteria number in dairy goats suffered from subacute rumen acidosis (SARA) were studied. Six lactating goats fitted with permanent ruminal cannulas with an average body weight of (32.00±1.21) kg at 2~3 years of age were induced in SARA by gradually increasing dietary concentrates. Then the animals were randomly divided into two groups, of which one was fed the combined additives (treatment group, 10 g disodium fumarate and 34 mg monensin) and another was not (control group). The rumen fermentation parameters were determined and bacteria were quantitated using the traditional rolltube technique and 16S rRNA oligonecleotoide probe hybridization. The results showed that the total volatile fatty acid concentration was significantly increased (P<0.05), and pH was kept stable after adding the combined additives. The numbers of  Lactobacillus  and  S.bovis  were decreased significantly (P<0.05), while the numbers of  S.ruminantium,  M.elsdeni  and  B.succinogenes  were significantly increased (P<0.05). It was concluded that adding disodium fumarate and monensin to diets in dairy goats during induced SARA period could improve the rumen fermentation, and the number of lactic acid utilizing bacteria was increased but the number of lactic acid producing bacteria was decreased by feeding combined additives under SARA.