The total flavone content was obtained from flowers and leaf of buckwheat (Fagopyrum esculentum Moench) by heating reflux method. The effects of the total flavone extract on the protein tyrosine phosphatase 1B (PTP1B) expression in type 2 diabetic rats were evaluated by immunofluorescence, western blotting and real-time quantitative PCR. The results suggested that the total flavone fraction from buckwheat flowers and leaves can significantly decrease the PTP1B expression in liver.