Abstract： Chronic atrophic gastritis（CAG）is a complex condition characterized by a mixture of deficiency and excess due to the prolonged illness affecting the collaterals. The eliminating the old and generating the new method aims to remove pathological substances from the body through various means while replenishing qi and protecting the stomach to restore normal physiological functions，thereby achieving the effects of generating new blood，new collaterals，and new tissues. The authors believe that CAG is often a syndrome of mixed deficiency and excess， characterized by qi deficiency and stagnation，and the intermingling of phlegm，turbidity，and blood stasis. Treatment should be centered on the theory of eliminating the old and generating the new， targeting specific pathological mechanisms with methods such as soothing the liver and harmonizing the stomach， removing blood stasis and unblocking the collaterals， and resolving phlegm and eliminating dampness to eliminate internal pathogens and promote the recovery of gastric mucosa and its functions. At the same time， replenishing qi and protecting the stomach helps to restore bodily functions and facilitate the removal of pathological substances，thus allowing the regeneration of new membranes.