The fermentation processing of traditional Chinese medicines (TCMs), as an important processing method for TCM, originated from the ancient brewing technology. It has a long history in China. Fermented TCMs (FTCMs) are widely applied among folks for preventing and treating many diseases. There are many kinds of TCM processed by spontaneous fermentation, including Massa Medicata Fermentata, Rhizoma Pinelliae Fermentata, Red fermented rice, Semen Sojae Praepaaratum, Mass Galla chinesis et camelliae Fermentata and Pien Tze Huang. This essay summarizes historical origin, main varieties, the effect of microbial strains, current processing techniques and existing problems of FTCM, and look into the prospect of modern development of FTCMs.