Tongue of stomach cancer patients usually does not have obvious changes, while some patients may have thick tongue coating, change of tongue color, bad breath and so on. Gastric cancer is originated from gastric epithelial cells and belongs to malignant tumors in digestive tract, which is usually related to various factors such as age, Helicobacter pylori infection, poor diet, mental stress, smoking and alcohol stimulation. Early stage stomach cancer patients may not have any change in their tongue. As the disease develops, stomach cancer patients will suffer from indigestion, which will lead to deficiency of microelements, change in tongue color and thickening of tongue coating. Advanced gastric cancer patients who suffer from Helicobacter pylori infection for a long time may even have bad breath. For the treatment of gastric cancer patients, reasonable treatment plan can be formulated according to tumor staging, typing, physical condition and other factors.