Abstract： The authors discussed the basic theory and mechanism of moxibustion from the aspects of warming and unblocking，warming and supplementing，radiation effect of moxibustion，and the pharmacochemical effect of moxibustion products. The effect of moxibustion starts with warm stimulation；the mechanism is unblocking meridian and collateral；the main mechanism of various curative effect of moxibustion is unblocking by warming. For many diseases that are mainly caused by blocked meridian and collateral as well as stagnation of qi and blood， moxibustion is conducive to disease prevention and health care with wide application.