Atrophic gastritis C3 is represented by atrophy that has approached the cardia. chronic atrophic gastritis is one of the most common clinical conditions. The endoscopic classification of chronic atrophic gastritis can be divided into closed atrophy and open atrophy, with closed atrophy represented by C and open atrophy represented by the letter O. C can be divided into C1, C2 and C3; O can be divided into O1, O2 and O3. closed atrophy can appear as C1 when it is confined to the gastric sinus, C2 when the atrophy exceeds the gastric angle and invades the lesser curvature of the gastric body, and C3 if the atrophy develops further and approaches the cardia and does not exceed the cardia. There are many causes of chronic atrophic gastritis, the most common being H. pylori infection. For the treatment of chronic atrophic gastritis, H. pylori testing should be performed, and positive patients should be treated with anti-H. pylori therapy, and electronic endoscopy should be performed annually to observe whether the atrophy progresses further and to prevent the emergence of early gastric cancer.