Based on Guide to Clinical Practice with Medical Records,this paper analyzes and summarizes Ye Tianshi’s thoughts of preserving stomach yin. His theory of stomach yin advocates the divided treatment of spleen and stomach,and pays attention to the preservation of stomach fluid. During the preservation of stomach yin,it also needs to protect stomach qi and stomach yang. On this basis,the concrete reflection of Ye Tianshi’s theory of stomach yin in the treatment and medication are summarized. The commonly used treatment methods include the therapy of clearing fire and moistening stomach,therapy of increasing fluid and moistening dryness,therapy of invigorating liver and regulating stomach and therapy of moistening stomach and benefiting lung.