Gastric cancer is one of common malignant tumors in clinic. It has high incidence, high mortality and poor prognosis. Generally, gastric cancer is divided into early gastric cancer (EGC) and advanced gastric cancer. The 5-year survival rate of EGC is higher than that of advanced gastric cancer. In recent years, with the continuous development of science and technology, a variety of medical instruments and technologies have been updated, greatly promoting the detection rate of EGC, reducing the rate of EGC missed diagnosis. This article reviews the progress of EGC endoscopic diagnosis.