To investigate the effects of dietary fiber on growth performance and digestive physiology function in piglets. Ninety piglets (Duroc×Landrace×Jia) with an initial body weight of (13.37±1.28) kg were randomly allotted to 3 treatments with 3 replicates of 10 piglets. Pigs were fed with diets containing 2.91% (low fiber level group, LF), 4.28% (middle fiber level group, MF) and 5.91% (high fiber level group, HF) crude fiber, respectively. The experiment lasted for 33 days. The results indicated that ADG, ADFI and F/G had no significant difference among 3 groups (P>0.05), there was a tendency for reduced diarrhea frequency in the piglets in MF group and HF group. Digestibilities of gross energy and crude protein in the piglets in HP group were the lowest among 3 groups, and digestibilities of NDF and ADF were the highest, the difference was very significant compared with LF group (P<0.01); pancreas, stomach and duodenum index, the activities of chymotrypsin in the pancreas and amylase and proteolytic enzyme in the duodenum were the highest, the difference was significant compared with LF group (P<0.05). In conclusion, higher content of dietary fiber had no effect on growth performance in the piglets and could decrease diarrhea frequency; and development of the digestive tract as well as the activities of digestive enzymes was promoted.［Chinese Journal of Animal Nutrition, 2009，21(6）:816-821］