This study is a multi-centered, three-armed, randomized, double-blinded, controlled study, namely, the oral trial drug favipiravir tablets plus chloroquine phosphatetablets tablets group (combined group), the oral trial drug favipiravir tablets group (pirovir group), and the oral placebo treatment group (control group). The total number of enrolled cases in this study was set at 150.

During the treatment, the clinical data of the subjects were collected, the changes of viral load and biochemical indicators were detected, and the outcome of the subjects was monitored.

The main indicators of efficacy include improvement or recovery of respiratory symptoms and viral nucleic acid shedding. The rate of progression to severe disease, duration of fever, peripheral blood index and improvement time of pulmonary imaging were the secondary indicators to evaluate the efficacy.

Statistical analysis was performed at the middle and final stages of the study to evaluate the efficacy and safety of favipiravir tablets combined with chloroquine phosphatetablets tablets in the treatment of novel coronavirus pneumonia.

Inclusion Criteria:

• Male and female, 18-75 years old
• Patients previously diagnosed with novel coronavirus pneumonia: the course of illness is no more than 14 days; if the course of the disease was more than 14 days, patient meets one of the following conditions can also be included in the group: (1) No apparent absorption or progression of chest radiograph was observed within 7 days; (2) respiratory symptoms (chest tightness, or cough, or breathing difficulties); (3) Test for viral nucleic acid positive within 3 days.
• informed consent should be signed by the participate or an authorized agent
• Agree to clinical samples collection
• Female or male subjects of childbearing age agree to take effective contraceptive measures within 3 months of the last oral medication to ensure that female or male partners of childbearing age do not become pregnant

Exclusion Criteria:

• Severe vomiting or difficulty ingesting medication
• Woman who are pregnant or during lactation
• Patients received lopinavir/ridonavir, ribavirin, interferon and monoclonal antibody specific antiviral drugs three days before enrollment
• Cases of respiratory failure requiring mechanical ventilation
• Shock
• Combined with other organ failure and requires ICU care
• Clinical prognostic non-survival, palliative care, or in deep coma and no have response to supportive treatment within three hours of admission