Objective To investigate the pathogenic microorganism,clinical characteristics of infectious endocarditis(IE),in order to improve the level of diagnosis. Method This was a retrospective study of 162 cases of IE collected in our hospital. Result ①Congenital heart disease accounted for 94.4% of the underlying diseases while 9 patients has no underlying heart disease;②149 cases were treated with bacterial culture,the outcome was positive in 82 cases(55%),among which 47 patients were infected with streptococcus,17 with staphylococcus,6 with Gram-negative bacterium,3 with enterococcus faecalis,4 with mixed bacteria;③Fever was the most common clinical manifestation,which occurred in 148 patients. 98 patients have fevered last for one month and the most up to one year. 74.7% cases hemogram was raised;Other clinical manifestations include 69 cases microscopic hematura,21 cases urinary occult blood test(+++),123 cases anemia,121 cases with valve excrescence,cerebral infarction in 15 cases. While 4 patients had cerebral infarction as first symptom,spleen infarction in 4 cases,1 case spleen infarction combined with cerebral hemorrhage,1 case spleen infarction combined with left kidney infarction. Conclusion For patients with long time fever,anemia,occult blood test intensive positive,cardiac neoplasm IE was easy diagnosed;but for those patients had spleen,kidney,cerebral infarction or cerebral hemorrhage as first symptom,should be consider IE.