Systematic Chinese Materia Medica is based on the thought of “big traditional Chinese Materia Medica” of Professor LING Yikui，the founder of modern Chinese Materia Medica discipline.It is a discipline of the occurrence，development，and changes of the key elements of complex system of Chinese Materia Medica，studying the variety，quality，pharmaceutical production，drug property，efficacy，and application.This paper discusses the scientific connotation of systematic Chinese Materia Medica and reports the research practice of Herba Leonuri under the guidance of systematic Chinese Materia Medica.