[Objective] To investigate a propyl-alcohol ammonium sulfate aqueous two-phase system coupling with ultrasonic for extraction of total flavonoids from bamboo leaf. [Method] The propyl-alcohol ammonium sulfate aqueous two-phase system coupling with ultrasonic was used to extract and separate the total flavonoids from bamboo leaf. The effects of the ammonium sulfate and propanol content,ultrasonic time and fluid-solid ratio on the extraction yield of flavonoids were also studied. [Result] The optimum extracti...