Abstract: Characterization of Chinese medical properties is the key basis for guiding modern study in drug property discovery. However, lack of appropriate guidance limits current studies of external Chinese Medicine(CM). Based on the study progress of Chinese medical properties and the characteristics of external CM, three key elements of "component-delivery-efficacy" are proposed based on biopharmaceutical thoughts. Using such characterization model, drug delivery can be firstly regarded as the key factor between the component and the efficacy under the external route. Under the guidance of "compound-delivery-efficacy", essential oils (EOs) from herbs with "hot" property was found to possess higher penetration enhancement effect compared to other properties. The results revealed the rationale of the proposed three-element theory. This theory may lead a new strategy in scientific research, clinical application, and development of external CM products.