Abstract： Objective To establish a rat model of chronic atrophic gastritis and explore the factors inducing atrophy.Methods In accordance with repeated orthogonal design of L8(27), 60% alcohol and 20mmol/L sodium deoxycholate (served as factor A), 0.05%-0.1% ammonia water (factor B), 0.05% indomethacin (factor C) were given, alone or in combination, to rats in three experiments for 3 months, 6 months or 9 months respectively. Then the rats were dissected, and their pathologic changes of the gastric mucosa were assessed.Results Typical signs of chronic atrophic gastritis (CAG) were found in all rats which were treated with factor A, B, C alone or in combination for 6 or 9 months. No significant difference of pathologic changes of gastric mucosa was found between the rats treated for 6 months and those for 9 months. No obvious CAG signs were found in the rats treated with factor A, B, C for 3 months.Conclusion Sixty percent of alcohol, 20mmol/L sodium deoxycholate, 0.05%-0.1% ammonia water and 0.05% indomethacin given to Sprague-Dawley rats for 6 months can successfully establish the animal model of CAG. Prolongation of the model-establishment time is not able to further facilitate the atrophy of gastric mucosa.