Adulterant herbal materials are a threat to consumer safety. In this study, we used DNA barcoding to investigate the proportions and varieties of adulterant species in traditional Chinese medicine (TCM) markets. We used a DNA barcode database of TCM (TCMD) that was established by our group to investigate 1436 samples representing 295 medicinal species from 7 primary TCM markets in China. The results indicate that ITS2 barcodes could be generated for most of the samples (87.7%) using a standard protocol. Of the 1260 samples, approximately 4.2% were identified as adulterants. The adulterant focused on medicinal species such as Ginseng Radix et Rhizoma (Renshen), Radix Rubi Parvifolii (Maomeigen), Dalbergiae odoriferae Lignum (Jiangxiang), Acori Tatarinowii Rhizoma (Shichangpu), Inulae Flos (Xuanfuhua), Lonicerae Japonicae Flos (Jinyinhua), Acanthopanacis Cortex (Wujiapi) and Bupleuri Radix (Chaihu). The survey revealed that adulterant species are present in the Chinese market, and these adulterants pose a risk to consumer health. Thus, regulatory measures should be adopted immediately. We suggest that a traceable platform based on DNA barcode sequences be established for TCM market supervision.