1. Investigator makes a decision that trial participation is not in patients' best interest, or any condition that does not allow the protocol to be followed safely, 2. As judged by investigator historic or current diseases that may have impact on the subjects participation of the study or the study outcome. These diseases include but not limited to cadiac diease and arrhythmia and QT prolongation), neurological disease psychiatric disease,active bleeding, serious malnutrition and endocrine disease, currently complicated with serious respiratory disease or that seriously affect immune system, such as flu, COPD, asthma, HIV infection, blood system disease, or splenectomy, organ transplantation etc., 3. Severe liver disease (AST>3 ULN), 4. Patients with known severe renal impairment (estimated glomerular filtration rate <=60 mL/min/1.73 m2) or receiving continuous renal replacement therapy, hemodialysis, peritoneal dialysis, 5. QT elongation, 6. Allergic to chloroquine or hydroxychloroquine, 7. Pregnant or breastfeeding, or positive pregnancy test in a predose examination, 8. Will be transferred to another hospital within 72 hours, 9. Receipt of any experimental treatment for 2019-nCoV (off-label, compassionate use, or trial related) within the 14 days prior to the time of the screening evaluation.

1. Investigator makes a decision that trial participation is not in patients' best interest, or any condition that does not allow the protocol to be followed safely, 2. As judged by investigator historic or current diseases that may have impact on the subjects participation of the study or the study outcome. These diseases include but not limited to cadiac diease and arrhythmia and QT prolongation), neurological disease psychiatric disease,active bleeding, serious malnutrition and endocrine disease, currently complicated with serious respiratory disease or that seriously affect immune system, such as flu, COPD, asthma, HIV infection, blood system disease, or splenectomy, organ transplantation etc., 3. Severe liver disease (AST>3 ULN), 4. Patients with known severe renal impairment (estimated glomerular filtration rate <=60 mL/min/1.73 m2) or receiving continuous renal replacement therapy, hemodialysis, peritoneal dialysis, 5. QT elongation, 6. Allergic to chloroquine or hydroxychloroquine, 7. Pregnant or breastfeeding, or positive pregnancy test in a predose examination, 8. Will be transferred to another hospital within 72 hours, 9. Receipt of any experimental treatment for 2019-nCoV (off-label, compassionate use, or trial related) within the 14 days prior to the time of the screening evaluation.