OBJECTIVE To study on the identification of traditional Chinese medicine of Macleaya cordata(M. cordata) and its similar varieties. METHODS By consulting the ancient herbal books and modern literature, this paper systematically combs and studies the M. cordata. The morphological identification, microscopic identification, physiochemical identification, molecular identification were used to identify M. cordata and its similar varieties. RESULTS Obtained M. cordata herbal textual research data. There were some differences between M. cordata and Macleaya microcarpa(M. microcarpa) and other similar varieties in traits, microscopic, physicochemical and molecular characteristics. Molecular identification results showed that the length of the rbcL gene of M. cordata were 600 bp to 603 bp, with the average GC content ranging from 43.95% to 44.28%. There were significant differences in the variation sites between M. cordata and other similar varieties, and the variation sites with M. microcarpa were the least. The interspecific genetic distance between M. cordata and its similar varieties was greater than its maximum intraspecific genetic distance. NJ analysis results of rbcL could effectively distinguish M. cordata from other similar varieties accurately and quickly. There were significant differences in the secondary structure of rbcL between M. cordata and its similar varieties. CONCLUSION The traditional Chinese medicine identification methods of M. cordata, M. microcarpa and other similar varieties are constructed, which provides experimental basis for the variety identification of M. cordata and the subsequent development of traditional Chinese medicine resources.