Objective To summarize the clinical characteristics and investigate the main causes of hemoptysis of adult patients admitted to the West China Hospital of Sichuan University. Methods A retrospective study was conducted and patients admitted to the West China Hospital of Sichuan University mainly for hemoptysis between 1stJuly 2009 and 30th August 2012 were included. The etiology, patient age, hemoptysis severity, history of smoke, diagnostic evaluation were screened from their medical records and analyzed. Results 418 patients（M：F 2:1） were included for study, with a mean age of 53.9±15.5 years. Explicit diagnosis were made in 314 patients. The most frequent underlying disease was bronchiectasis (61.5%), followed by lung cancer (8.6%), pulmonary tuberculosis (6.4%) and pneumonia (5.7%). All of the 24 patients with primary lung cancer were over 50 years old. Positive smoking history was found in 17 patients with lung cancer, 13 of them smoking≥40 packyears. And all the 8 patients with benign tumor were less than 50 years old without history of smoking. About half of the 20 pulmonary tuberculosis patients were between 31 years and 50 years old. 101 patients had anemia, 771.3% mild, 26.7% moderate, and 2.0% severe. All of the 418 patients have taken CT scan, with a positive diagnostic rate of 59.1% when employed alone. 149 patients finished the fiberoptic bronchoscopy, with a positive diagnostic rate of 25.5% when employed alone. However, when combining the CT scan and the fiberoptic bronchoscopy, the positive diagnostic rate increased to 100%. Conclusion Bronchiectasis is the main cause of hemoptysis in adult patients. Lung cancer and bronchitis are more frequently in smokers than that in non-smokers. The older, especial those with a heavy smoking, are more likely to suffer lung cancer. The occurrence of hemoptysis was found higher in younger than that in older. The combined use of CT scan and the fiberoptic bronchoscopy has the best value in diagnosing hemoptysis.