Abstract: Objective The study aimed to analyze the etiology of small intestinal bleeding, to compare the differences of factors related anemia among patients with different diseases or with different examinations, and to evaluate the potential factors correlated to operation. Methods Sixty one patients were included in the study. The double-balloon enteroscopy （DBE） was performed in 37 patients either with the oral/anal route alone or with combined approaches and the wireless capsule endoscopy （CE） was performed in 24 patients. All the patients received conventional blood tests. Results The detection rate of DBE and CE was 78.4% and 75% respectively. The difference was not significant（χ²=0.11,P>0.05）. The main causes were vascular lesions and ulcers, which were 26.2% （16/61） and 21.3% （13/61） respectively. A total of 17 patients underwent surgery. Tumors were the main cause of operation, accounting for 52.9% （9/17）. For patients with CE examination, the hemoglobin was lower in the group with operation（68.50±5.80） g/L vs. （92.40±27.58） g/L,P=0.002. For patients with DBE examination, the heart rate at admission was higher in the group with operation（93.08±16.65） beats/min vs. （80.71±10.98） beats/min,P=0.03. There was a positive correlation between heart rate and operation（r=0.366,P=0.026）. Conclusion The vascular lesions and ulcer were the main causes for small intestinal bleeding. Tumors were the main cause of operation. Decreased hemoglobin and increased heart rate may be effective indicators for predicting the necessary of surgery.