Objectives To provide the basis for determining the threshold of prophylactic platelet transfusion of on patients with hematologic disease by analyzing the impact of different threshold of prophylactic platelet transfusion on patients. Methods The eligible patients were divided into two groups based on the platelet counts of patients after platelets transfusion, in group A platelet counts remained at ≥10×109 /L, in group B it maintained at ≥20 × 109 /L. The improvement of bleeding, blood transfusion effect and the proportion of produced platelet antibodies in both groups were compared. Results The infusion numbers, the dose of infusion and the rates of produced platelet antibodies in group A were all lower than that of patients in group B. However, there was no significantly difference on the bleeding between two groups. Conclusion For these stable patients with hematologic diseases and no obvious risk factors, using 10×109/L trigger as a prophylactic platelet transfusion threshold might be safe.