ABSTRACT
This paper is based on the literature of the last ten years by summarizing and analyzing the progress in the study of Rehmanniae Radix, focusing on the research progress are reviewed at the dynamic changes of the main Chemical indicators of Rehmanniae Radix Preparata, objective expression of four kinds of processed products (Steamed, steamed with wine, wine stew, ancient law (steamed for nine times and shined for nine times) ) and the objective expression of four kinds of processed products and the change of the pharmacological effects.There are many objective expression methods for processing end points of different processed products of Rehmanniae Radix Preparata, But processing are unclear until now. Innovative research on standardized unification and new research ideas are needed.