200 one-day-old Bairi chickens were divided into 4 groups randomly, and they were fed with diet added Bamboo Leaf Flavonoids（BLF）at 0, 0.05 %, 0.25% and 0.45% respectively for 28 days. At the end of the experiment, blood samples were collected from hearts of chickens in order to determine part biochemical indexes. The results indicated that contents of glucose and triglycerides decreased very significantly（P＜0.01） by the differentdose of BLF. As for middle dose of BLF, contents of total protein and globulin increased, while the ratio of albumin /globulin decreased very significantly（P＜0.01）. The activity of glutamic oxalocetie transaminase, r-glutamyl transfer-ase, and creatine kinase decreased, while the activity of alkaline phosphatase increased at different degree as wellas the contents of urea and uric acid in serum decreased significantly（P＜0.01, P＜0.05） by adding BLF. As for lowdose of BLF, the contents of creatinin, Ca and Mg in serum decreased significantly（P＜0.05, P＜0.05, P＜0.01）. Besides serum protein and ALP, other adjustable indexes in serum could be reduced by BLF.