Abstract: This experiment was conducted to assess the supplementation of Lactobacillus fermentum F-6 with different levels in basal diet on serum antioxidant capacity and volatile fatty acid（VFA） in intestine of broiler chickens. A total of 240 1-day-old healthy AA broiler chickens were included in this study and were randomly divided into 4 groups（3 experimental groups and 1control group）. No significant differences were observed in initial body weight between the chickens of different groups（P〉0.05）.The same basal diet was supplied for each group; however, the basal diet of the three experimental groups was supplemented with2.0×10~5, 2.0×10~6 and 1.0×10~7 CFU/m L of Lactobacillus fermentum F-6, respectively. No additions of Lactobacillus fermentum F-6 were made in basal diet of the control group. The serum content of MDA and SOD as well as content of VFA in intestine of 21-day-old and 42-day-old broiler chickens in each group were determined. The results showed that the serum content of SOD of21-day-old chickens of experimental group 3 was significantly higher than that of control group（P〈0.05）; the serum content of SOD of 42-day-old chickens in experimental group 2 and 3 were significantly higher than that in control group（P〈0.05）; the content of acetic acid and total volatile fatty acid（TVFA） in cecum and ileum of 21-day-old and 42-day-old broiler chickens of all experimental groups were significantly higher than that in control group（P〈0.05）; except for experimental group 1, the content of butyrate in cecum and ileum of 21-day-old and 42-day-old broiler chickens of the other experimental groups were significantly higher than that of control group（P〈0.05）. It was demonstrated that the supplementation of Lactobacillus fermentum F-6 in basal diet was able to improve the serum antioxidant capacity and increase the level of VFA in intestine of broiler chickens, which was potential to be developed as a new type of additive.