To study the effects of sodium butyrate (SB) supplementation on performance, pH and concentration of volatile fatty acids (VFA) in broilers, four hundred and eighty 1-day-old AA broilers were divided into four groups (three replicates for each group, and forty broilers per replicate). Broilers were fed the following diets: control diet group was without any SB and antibiotics; antibiotics group was supplemented with antibiotics (zinc bacitracin 40 mg/kg+colistin sulfate 8 mg/kg) into the basal diet; powder sodium butyrate (PSB) group was consisted of control diet+200 mg/kg PSB; coated sodium butyrate (CSB) group was consisted of control diet+200 mg/kg CSB. Average daily gain and average daily feed intake (ADFI) of broilers at 21 and 42 days of age were recorded. At 14 and 35 days of age, twelve broilers were randomly selected to determine intestinal pH and VFA, respectively. The results showed as following: addition of SB significantly affected ADFI and CSB, and decreased F/G (6.25%) in grower period (21~42 days of age, P<0.05). SB showed a decreasing tendency of the gut pH; and 200 mg/kg CSB supplementation could significantly improve the acetic acid concentration by 10.39%, propionic acid concentration by 33.61% and butyrate concentration by 36.80% in the intestine. In conclusion, SB could increase feed conversion rate to improve growth performance, decrease intestinal pH, and increase intestinal VFA concentration. And the effects of CSB were better than those of PSB.［Chinese Journal of Animal Nutrition, 2010，22（3）:675-681］