1) Cases with severe vomiting and difficulty in taking drugs orally or causing difficulty in taking drugs after oral administration, 2) Pregnant and lactating women, 3) The subjects received specific antiviral drugs such as lopinavir / lidonavir, ribavirin and monoclonal antibody within one week before admission, 4) Cases with no hope of survival, hospice care only, or deep coma and no response to supportive treatment within three hours after admission, 5) Cases of deep shock and respiratory failure, 6) Severe liver diseases (such as child Pugh score >= C, AST more than 5 times of the upper limit of normal), 7) Patients with severe renal insufficiency (estimated glomerular filtration rate <= 30ml / min / 1.73m2) or undergoing continuous renal replacement therapy, hemodialysis, peritoneal dialysis, 8) Patients with known allergic reactions or contraindications to chloroquine phosphate, 9) The doctor decided that it was not in the best interests of the subjects to participate in the study, or there was any situation in which the agreement could not be followed safely.

1) Cases with severe vomiting and difficulty in taking drugs orally or causing difficulty in taking drugs after oral administration, 2) Pregnant and lactating women, 3) The subjects received specific antiviral drugs such as lopinavir / lidonavir, ribavirin and monoclonal antibody within one week before admission, 4) Cases with no hope of survival, hospice care only, or deep coma and no response to supportive treatment within three hours after admission, 5) Cases of deep shock and respiratory failure, 6) Severe liver diseases (such as child Pugh score >= C, AST more than 5 times of the upper limit of normal), 7) Patients with severe renal insufficiency (estimated glomerular filtration rate <= 30ml / min / 1.73m2) or undergoing continuous renal replacement therapy, hemodialysis, peritoneal dialysis, 8) Patients with known allergic reactions or contraindications to chloroquine phosphate, 9) The doctor decided that it was not in the best interests of the subjects to participate in the study, or there was any situation in which the agreement could not be followed safely.