To illustrate the theoretical basis of warming and dredging function of moxibustion from the treatment features, indications and effects. The causation of moxibustion is warming stimulation, and the mechanism of action is dredging meridians and collaterals. In a word, promoting the dredging function by warming is the main mechanism of therapeutic effect of moxibustion. It is summarized that warming and dredging function of moxibustion has the differences in weakness and strongness, and degree of urgency; and the initial study of clinical application is discussed as well.