Effects of dietary different level of Yucca schidigera extract (YSE) on small intestinal mucosal morphology, activities of chymous digestive enzymes and apparent metabolic rates of nutrients of broilers were studied to provide a theoretical basis for determining YSE appropriate dosage in broiler diets. One hundred and twenty-eight one-day-old Arbor Acres (AA) broilers were randomly assigned to 4 groups with 4 replicates per group and 8 chicks per replicate after 14 days pre-feeding period with basal diets. The supplemental levels of YSE in diets were 0 (control group), 100, 200, and 300 mg/kg, respectively. The experimental period lasted for 28 days. At 28 and 42 days of age, two birds in each replicate were selected randomly and slaughtered, and the front parts of duodenum, jejunum and ileum were removed in order to observe small intestinal mucosal morphology, and small intestinal chyme was collected for analyzing the activities of digestive enzymes. At 35 days of age, one bird in each replicate was selected for metabolic experiment. The results showed as follows:compared with the control group, 1) diet added 100 mg/kg YSE significantly increased jejunum villus height (VH) of broilers at 28 days of age and duodenum VH and villus height/crypt depth (V/C) at 42 days of age (P<0.05). 2) Diet added 200 mg/kg YSE significantly increased the activities of trypsin (TRY) and lipase (LPS) in ileum chyme and LPS in duodenum chyme of broilers at 42 days of age (P<0.05). 3) Diet added 200 mg/kg YSE significantly increased the apparent metabolic rates of dry matter (DM) and crude protein (CP) of broilers (P<0.05), but diet added 300 mg/kg YSE significantly decreased CP apparent metabolic rate (P<0.05). What's more, the apparent metabolic rates of calcium (Ca) and phosphorus (P) in 100 and 200 mg/kg YSE groups showed an increasing trend but those in 300 mg/kg YSE group showed a decreasing trend (0.05 ≤ P < 0.10). In conclusion, the appropriate dosage of YSE in broiler diets is 100 to 200 mg/kg based on the digestive and metabolic functions.