This is a randomized study to evaluate the safety and feasibility of early de-escalation of empirical antibiotics treatment in neutropenic fever patients undergoing hematopoietic stem cell transplantation (HSCT). In case of afebrile for 72 hours with empirical antibiotics treatment, patients will be randomized into 2 groups. In the early de-escalation group, antibiotics treatment will be stopped and prophylaxis with levofloxacin will be resumed. In the control group, the empirical treatment will continue until recovery of neutropenia or at least for 7 days.

This is a randomized study to evaluate the safety and feasibility of early de-escalation treatment of empyrical antibiotics treatment in neutropenic fever patients undergoing hematopoietic stem cell transplantation (HSCT). All patients undergoing HSCT will receive levofloxacin as regular prophylaxis. After patients develop neutropenia fever, the empirical antibiotics protocol will be impenem. In case of persistent for 48 hours, vancomycin will be added. If afebrile is achieved for 72 hours, all patients will randomized into early de-escalating group or control group. In de-escalating group, the empirical antibiotics treatment will be stopped and then levofloxacin prophylaxis will be resumed. In the control group, the empirical antibiotics treatment will be continue until recovery of neutropenia or at least 7 days.

Inclusion Criteria:

• Age ≥18，patients undergo hematopoietic stem cells
• Patients with neutropenic fever: T≥38.5°C once or T≥38°C twice a day with ANC <0.5x109/L or predicted to be <0.5x109/L in 24 ~48 hours；
• Patients achieved afebrile （T<37.5°C）for at least 72 hours；
• Inform consent given

Exclusion Criteria:

• Patients with neutropenic fever with documented blood stream infection, skin and soft tissue infection, pneumonia and catheter associated infection.
• Patients with septic shock
• Levofloaxin allergy or contra-indication