Longitudinal ulcer of esophageal mucosa covered with white moss suggests localized injury of esophageal mucosa, which may be benign ulcer of esophageal mucosa or cancerous. 1. Benign esophageal ulcer: if the surface of ulcer is covered with white moss, but there is no obvious hyperplasia, bulge, hardening of tissue mucosa around the ulcer, or no abnormal redness or swelling, then it may be considered as benign ulcer, but this kind of ulcer belongs to the more serious situation, and may have symptoms such as discomfort in swallowing, choking sensation, nausea, vomiting, bleeding, and so on. 2. Esophageal cancer: if there is white moss on the surface of the ulcer, and at the same time, the mucosa around the ulcer appears hyperplasia, bulge, erosion, hardening, and does not heal for a long time, and accompanied by long-term symptoms such as loss of appetite, weight loss, blood in stool, etc., it suggests that there is the risk of cancer, and the biopsy under gastroscope should be carried out for a clear diagnosis. Longitudinal ulceration of esophageal mucosa with white moss, it is recommended to consult a doctor in time to make a clear diagnosis and carry out targeted treatment under the guidance of a doctor.