The liver is the unyielding viscus, which governs the free flow of qi and stores the blood. It is yin in form but yang in function, and prefers free activity. Professor Tian Delu has developed his academic theory on relieving digestive diseases by treating liver problems, which can be categorized into the following aspects: 1. It is suggested to soothe the liver and rectify qi when the free movement of qi is restricted due to liver constraint, to unblock the liver collaterals for diseases caused by qi stagnation and blood stasis, and to emolliate the liver in the case of disharmony between its form and function. 2. The liver and spleen should be regulated simultaneously for wood-earth diseases, the principles for which include banking up the earth to relax the liver, banking up the earth to discharge the wood, banking up the earth to dissipate the liver; discharging the liver to harmonize the stomach, and discharging and directing downward liver qi. 3. If hyperactivity of the liver hurts the lung, causing coughing, wheezing and panting, like metal is sounded by the blows of wood, measures should be taken to inhibit liver qi.