With the development of modern molecular biology techniques and the progress of metagenomic and metabonomics, gastrointestinal tract flora and its metabolic research are taken more seriously. Gastric cancer, as the fifth most common cancer and the third mortality rate of cancer-related death in the world, and gastrointestinal tract flora are getting recognized. The number and the type of microorganism are the most in the gastrointestinal microecosystem, and their balance play aimportant role in human health.Early humans think stomach is terile. Along with the in-depth study of the relationship between helicobacter pylori infection and human gastric cancer has been gradually revealed as well as the relationship between human gastrointestinal tract flora and gastric cancer. The study confirmed that gastrointestinal tract flora can participate in nutrition, metabolism and immune function. Changes in gastrointestinal tract flora can also lead to the occurrence and development of inflammation. If the spleen and the stomach are incoordination, gastrointestinal tract flora may disorder inevitablely. Therefore, traditional Chinese medicine can not only improve the incoordinated symptoms of spleen and stomach, but also adjust the gastrointestinal tract flora of patients with gastric cancer. In this paper, study on the relationship among gastrointestinal tract flora and gastric cancer and the role of traditional Chinese medicine is to be summarized.