To examine the flora samples from the tongue dorsum of the atrophic glossitis group and to discuss the relationship so as to provide a thinking pattern for therapy and a clue for deeper research.To collect personal information on 60 cases of atrophic glossitis and 40 cases of volunteers as control. The main items include general status, oral examination, salivary flow rate, pH value and bacteria test. All data were analyzed statistically.1) Among the 60 cases, 75.00% were female patients. Glosso-pain, dry mouth and taste loss were the most common symptoms. 2) In regard to the pathogenic factors, the systematic diseases were often visible, i.e. gastritis, coronary disease and anemia. 3) Oral hygiene of the patients was worse than that of the control group, the saliva flow rate and pH value were lower than that of the control. 4)The statistic analysis showed that the quantity of some bacteria of tongue dorsum and their detectable rate were different between the glossitis group and the control one, between the patients with atrophic glossitis who also suffered from different systematic diseases and the control group, and between the complete type and the partial type. These bacteria included Streptococcus sanguis, Stomatococcus, Staphylococcus aureus, Saccharomyces, etc.Atrophic glossitis is the consequence co-affected by host, circumstances of oral cavity and bacteria. The tangible relationship between atrophic glossitis and micro-ecological changes on glossal dorsum has not been confirmed yet, however, flora change on dorsum may have relations with occurrence, and development of the disease.