The whole process of gastroscopy includes preparation before examination, examination process and operation after examination. 1. Pre-examination preparations: at least 8 hours before the gastroscopy, fasting and water, and should be prepared to loose clothing, temporarily stop the use of anti-platelet aggregation drugs, such as aspirin. Oral antifoaming agents and local anesthesia drugs are required before the examination, and intravenous anesthesia is required for general anesthesia gastroscopy. 2. Examination process: the examination usually take the left lying position, will be slightly bent legs, the gastroscope through the examinee’s mouth into the stomach, in turn to observe the pharynx, esophagus, stomach, duodenum and other parts of the situation, and then the gastroscope will be pushed out, as appropriate, according to the condition of the pathology tissue examination. 3. Post-examination operation: generally fasting for 2 hours after the examination, if you do pathological tissue biopsy or polyp removal, you need to eat again after 4 to 6 hours as prescribed by the doctor. The whole process of gastroscopy is relatively complex, be sure to follow the instructions of the doctor and the precautions explained.