Objective: To guide the clinical rational use of Gypsum Fibrosum by study on its usual dosage in traditional Chinese medicine(TCM) decoction. Method: This paper collected TCM formulae containing Gypsum Fibrosum from ancient literatures

and constructed database of Gypsum Fibrosum by SQL Server 2008.This paper used Excel 2013 to screen Gypsum Fibrosum formulae with water decoction and oral administration

and SPSS 19.0 was adopted to calculate mode

frequency

mean

median and other parameters. Result: This study collected 3 546 formulae containing Gypsum Fibrosum from ancient literatures of TCM

and selected 672 decoction with dose of Gypsum Fibrosum.During these Gypsum Fibrosum formulae

formulae with dosage of Gypsum Fibrosum<15 g accounted for 47.92% of the total

<41.5 g accounted for 75.6% of the total

41.5-60 g accounted for 4.32% of the total. Conclusion: Raw Gypsum Fibrosum is mainly used in decoction containing Gypsum Fibrosum.The clinical dosage of Gypsum Fibrosum is relatively large before Song dynasty in ancient literatures of TCM formulae.This paper suggests that the commonly used dosage of Gypsum Fibrosum should be 7.5-41.5 g

its oversize dose should be 55-110 g.