Pneumocystis Pneumonia is increasing in Immunocompromised Non-HIV Infected Patients. The effects and safety of caspofungin and corticosteroids is not certain in this population. All Immunocompromised Non-HIV patients with respiratory failure were randomized into caspofungin and non-caspofungin group and corticosteroids and non-steroids group. The major outcome is 28 day mortality, the second outcome are time of respiratory rate decreases to less than 25 breath per minute, body temperature lower than 37.3℃.

Inclusion Criteria:

• Immunocompromised Non-HIV Infected Patients
• Partial arterial O2 pressure(PaO2)/FiO2≤300mmHg
• Diagnosed as Pneumocystis Pneumonia

Exclusion Criteria:

• younger than 16 years old
• severe organ failure
• allergic to sulfanilamide, caspofungin or corticosteroid