RESUMEN
To establish a quality constant evaluation system of Alismatis Rhizoma decoction pieces,in order to provide reference for regulating the market circulation of this decoction pieces. A total of 18 batches of Alismatis Rhizoma decoction pieces were collected from different pharmaceutical factories,and the morphological parameters of each sample were tested. The content of alisol B 23-acetate in Alismatis Rhizoma decoction pieces was determined by HPLC in the 2015 edition of Chinese Pharmacopoeia,and the parameters such as quality constant and relative quality constant were calculated. The quality constant range of 18 batches of Alismatis Rhizoma decoction pieces was 0. 390-2. 076. If 18 batches of Alismatis Rhizoma decoction pieces were divided into 3 grades,taking 80% of the maximum quality constant as first grade,50% to 80% as second grade,and the rest as third grade,then the quality constant of firstgrade samples was ≥1. 66,the quality constant of second-grade samples was ≥1. 04 and <1. 66,and the quality constant of third-grade samples was <1. 04. The established quality constant evaluation method is objective and feasible,which can be used to classify the grade of Alismatis Rhizoma decoction pieces and provide a reference method to control the quality of this decoction pieces.