In the case of small gastric cancer or pre-cancer, there are no obvious clinical manifestations, and some manifestations are indigestion, such as upper abdominal discomfort, abdominal flatulence, aversion, belching, abdominal pain and decreased appetite. These manifestations are not specific and are easily confused with benign lesions of the upper gastrointestinal tract, which are usually clinically diagnosed as benign diseases such as slow gastritis and functional dyspepsia, delaying the diagnosis. With the development of lesions, tumor enlargement and bleeding, the gastric function or general condition is affected before different degrees of blind manifestations appear, but they are not unique to gastric cancer, so without special examination, they are usually treated as benign gastric diseases. When the upper gastrointestinal manifestations are aggravated, the pain in the upper abdomen is aggravated after eating, the appetite is reduced, anemia, black stool, emaciation and weakness, and then the abdominal mass, pyloric obstruction, swollen supraclavicular lymph nodes, abdominal transport and other advanced manifestations and signs are presented, the time of useful and complete cure is lost. Some patients have mild pressure pain in the right side of upper abdomen. When the lesion is large and the ulcer involves the muscular layer, plasma membrane or outer layer of plasma membrane, the patient refuses to press on the upper abdomen and may present muscle severity and rebound pain. 2.Abdominal mass A mass can be found in any part of the appropriate gastric region in the upper abdomen, and cancer of the gastric sinus is more common in the right upper abdomen. The mass is firm and nodular in shape. When the tumor infiltrates into the surrounding arrangements, the mobility is significantly limited. If the primary tumor is accompanied by surrounding lymph node transport or pelvic tumor cultivation, nodes of bladder or uterine rectum transport can be found through anorectum. 3.Lymph node transport Besides intra-abdominal paraneoplastic lymph nodes, left supraclavicular lymph node transport rate is the highest, reaching about 10%, and axillary lymph nodes account for about 2%. 4.Wide cultivated transport Gastric cancer can be transported to liver, lung, bone, kidney and nervous system in late stage. When the tumor invades the plasma membrane and cancer cells fall off, there can be ascites and cancer cells can be detected. If the disease deteriorates further, there will be emaciation, bleeding, anemia, pyloric obstruction, hepatomegaly, jaundice, ascites and cachexia.