Objective To analyze the characteristics of the clinical dosage of Huangqi [Astragalus membranaceus（ Fisch.） Bunge. 黄芪]from Han dynasties till now. Methods The most representative medical works from each dynasty were selected. The usages of Huangqi were recorded using Microsoft Office Excel 2007 software. And data on name of formula

dosage of all medicinals

dosage of Huangqi

number of all medicinals

volume of water added

administration

etc. was entried. The information on Huangqi

including the frequency occurring in formulas

regular dosage

upper limit of regular dosage

lower limit of regular dosage

maximum dosage

minimum dosage

and average dosage were statistically analyzed. Results The maximum dosage of Huangqi fluctuated largely and reached the peak in Qing Dynasty（ 298. 4 g / day）. Other than that

the clinical dosage of Huangqi has been decreasing from Han and Tang Dynasties to Song Dynasty then remaining steady. Conclusion Large dosage of Huangqi was used to treat skin and muscular diseases

sequela of stroke

hemiplegia

amyasthenia

and rheumatism with deficiency syndromes. For other diseases

the dosage changed according to different symptoms.