Objective: To explore the occurrence of anemia in patients with ten common malignant tumors and the related risk factors. Methods: A retrospective analysis was performed in 15 612 patients with ten common malignant tumors admitted in Zhejiang Cancer Hospital from January 2016 to September 2016 by single factor analysis. Results: Among the 15 612 cases, there were 7 468 males (47.83%), 8 144 females (52.17%), and anemia occurred in 5 541 cases, accounted for 35.5% of all the cases with malignancy.Ovarian cancer, gastric cancer and esophageal cancer ranked top three in all types with occurrence of 57.9%, 53.1% and 49% respectively.According to the grading, mild to moderate (Grade 1-2) anemia accounted for 91.2% of the total cancer related anemia, while severe (Grade 3-4) consisted only a small proportion of 8.8%.The mean age of malignant tumor patients was (56.1±11.6)years old, and that showed a significantly difference between the anemia group and non-anemia group in patients' ages among lung cancer, colorectal cancer, gastric cancer and nasopharyngeal carcinoma(t=7.162, 2.486, 4.353, 2.926, all P<0.05). Gender analysis showed that male patients were more prone to cancer related anemia in esophageal cancer and lung cancer(χ²=91.034, 9.240, all P<0.05), and less likely in colorectal cancer, liver cancer and thyroid cancer(χ²=7.707, 6.629, 8.700, all P<0.05) (ovarian cancer, cervix cancer and breast cancer were excluded in this section for their none or rare incidence in male). Conclusion The patients with malignancy have a relative high occurrence of anemia.Caner related anemia is rather mild to moderate than severe, and tumor types, ages and genders were the risk factors of anemia in patients with malignancy.