This experiment was conducted to study the effects of dietary fiber levels on fecal indices and serum hormones and other biochemical indices of gestating sows. Thirty Yorkshire multi-parity sows, with similar parity and breeding time, were randomly divided into control group, treatment 1 and treatment 2 (the dietary fiber levels in early gestation were 4.14%, 5.27% and 6.06%, respectively, and 2.62%, 3.45% and 5.22% in late gestation, respectively). The experiment lasted for 114 days. The results showed that: 1) fecal moisture content in treatment 1 and treatment 2 was significantly higher than that in the control group in early gestation (P＜0.05 or P＜0.01), compared with control group, fecal pH and quantity of lactobacillus in treatment 2 were increased in early and late gestation （P＜0.05 or P＜0.01）, but quantity of Escherichia coli was decreased （P＜0.05）; 2) the digestibility of organic matter, NDF and ADF were increased in treatment 1 compared with the control group and treatment 2 in early gestation (P＜0.05 or P＜0.01); 3) serum triglyceride and total cholesterol in the control group were significantly higher than those in treatment 2 in early gestation (P＜0.05 or P＜0.01), and serum total cholesterol in the control group were significantly higher than that in the other groups in late gestation （P＜0.05 or P＜0.01）; 4) serum anti-oxidation capacity, activity of catalase and prolactin levels in the control group were significantly higher than those in treatment 2 （P＜0.05 or P＜0.01）. The results indicate that high dietary fiber levels don’t have active effects on improving fecal moisture content or decreasing fecal pH and don’t have active effects on improving anti-oxidation and prolactin levels, but have active effects on improving fecal bacterial composition, and decreasing serum triglyceride and total cholesterol. ［Chinese Journal of Animal Nutrition, 2010，22（6）:1529-1535］