Inclusion criteria:
Confirmation of 2019-nCoV infection by RT-PCR
Diagnosis of ARDS according to the Berlin definition of ARDS
Requiring supplemental oxygen,
PaO2/oxygen absorption concentration (FiO2) ≤ 300MMHG
Pulmonary imaging shows that the focused progress > 50% in 24-48 hours
Mild to Moderate 2019-nCoV pneumonia/ stay in the ICU <48 hours SOFA score between 2-3 point
Pneumonia that is judged by chest radiograph or CT
Exclusion criteria:
Severe allergies or allergies after 1st injection to stem cell preparations and their components
Patients with a malignant tumor, other serious systemic diseases, and psychosis Co-Infection of HIV, tuberculosis, influenza virus, adenovirus and other respiratory infection virus
Patients with previous history of pulmonary embolism
Liver or kidney SOFA score of more than 3 points; combined with other organ failure (need organ support),
Stage 4 severe chronic kidney disease or requiring dialysis (i.e. estimated glomerular filtration rate (eGFR) < 30)
Pulmonary obstructive pneumonia, severe pulmonary interstitial fibrosis, alveolar proteinosis, allergic alveolitis, and other known viral pneumonia or bacterial pneumonia
Continuous use of immunosuppressive agents or organ transplants in the past 6 months
In vitro life support (ECMO, ECCO2R, RRT)
Pregnant or lactating women
Uncontrolled underlying disease
Be thought by researchers to be inappropriate to participate in this clinical study (Expected deaths within 48 hours, uncontrolled infections)