Abstract: A total of 224 5-week-old healthy Yellow-feathered broilers with similar boby weight（367.9±4.53）g were randomly allocated into 4 groups (Ⅰ，Ⅱ，Ⅲ and Ⅳ) with 4 replicates per group and 14 broilers in each replicate. Group Ⅰ was the control group and fed the basal diet；Groups Ⅱ，Ⅲ，Ⅳ were experimental groups which fed the basal diets supplemented with 3.75‰，5.00‰ and 6.25‰ metabolic organic acids （based short-chain keto acid and organic)，respectively.The results showed that compared with the control group，the average daily gain of group Ⅲ was significantly increased (P＜0.05)，the feed-gain ratio of group Ⅳ was significantly decreased (P＜0.05). There were no significant effects on breast meat rate，leg meat rate and abdominal fat ratio in each group (P＞0.05)，however，it could improve serum total protein and albumin levels，reduce alanine aminotransferase content of 8-week-old broilers.Therefore，it could be seen that the product of metabolic organic acids could effectively improve the average daily gain，lower feed-gain ratio of broilers，and promote the growth of Yellow-feathered broilers by regulating the level of serum proteins and enzymes，its appropriate level of adding in diet was 5.00‰.

Key words: metabolic organic acid; Yellow-feathered broilers; growth performance; biochemical indexes