Objective To analyze the characteristics and regularity of the dosage of single-flavored traditional Chinese medicine decoction pieces, and to provide reference for determining the reasonable dosage range. Methods The dose distribution of single-flavored drugs with a frequency of more than 10％ of the total prescriptions from January to June2018 was investigated, and compare with the 2015 edition of the Pharmacopoeia of the People's Republic of China (hereinafter referred to as "Chinese Pharmacopoeia") and other recommended doses. Results There were 32 kinds of single-flavored traditional Chinese medicine decoction pieces, which accounted for more than 10％ of the total prescription. The top 5 dose distributions were 10 g, 15 g, 9 g, 30 g and 6 g, respectively, accounting for nearly 90％.These 32 pieces were not used in large-dose applications in our outpatient prescriptions, and there were some ultralow-dose applications; there were 21 pieces with more than 90％ of the doses in the scope of the Chinese Pharmacopoeia. In the clinical use of traditional Chinese medicine decoction pieces, there were cases of out of the scope of the Chinese Pharmacopoeia, but were not prominent. Conclusion The reasonable dosage ranges of commonly used traditional Chinese medicines needs further study; the clinical use of traditional Chinese medicine decoction pieces should consider both safety and dose-effect relationship.