Abstract:AIM:To evaluate the species of bacteria on the conjunctiva sac of the middle age and the elder of Han nationality in Ganzi district·METHODS:A total of 173 cases(346 eyes) of the middle age and the elder of Han nationality in Ganzi Tibetan Autonomous Prefecture were examined.The professional person embrocated the inferior palpebral conjunctiva.Then the secretion was inoculated on blood plate for 48hours,the bacteria was seperated and identified·RESULTS: The positive rate of the bacteria cultivation was 60.4.%(209/346).Totel 232 strains were cultivated.The most dominant was Staphylococcus epidermidis(115 strains,49.6%),the next was Corynebacterium(60 strains,25.9%).The positive rate of bacteria in the conjunctival sac of the elder in Guzan and Lucheng town of Kangding County were 69.2% and 65.8%,the difference was not statistically significant(χ2=0.1709,P>0.05).The positive rate of the elder in Gar town of Jiulong County was 44.3%,compared with the ones in Guzan and Lucheng town was lower.The difference was statistically significant(Guzan vs Gar:χ2=13.2002,P<0.05;Lucheng vs Gar:χ2= 9.6869,P<0.05)·CONCLUSION:Bacteria could be found in most people’s conjunctiva of Han nationality,Staphylococcus epidermidis and Corynebacterium were the dominant strain on the conjunctiva of the middle age and the elder.Different district has different positive rate of the bacteria cultivation.