Study aim: Comparison of the efficacy and safety of Atazanavir/Ritonavir +HCQ with Lopinavir/Ritonavir +HCQ in patients with moderate COVID-19 Design: A randomized, double-blind, parallel phase 3 clinical trial is conducted on 128 patients with moderate COVID-19. Sealed envelope online software was used to randomize the allocation of treatment to the two intervention arms. Settings and conduct: Patients dyspnea and O2Sat less than 94% with possibly lung CT scan evidence of moderate COVID-19 pneumonia (Involvement of a maximum of 3 or 4 lung lobes with an area less than 1/3 size of each lobe or involvement of 1or 2 lobes with more involvement) and refer to Razi Hospital in Ghaemshahr in the 2020 epidemic, will be enrolled in the study. Researcher and final assessor are blind to the type of intervention and the allocation of treatment is under the supervision of a physician. Participants/Inclusion and exclusion criteria: Inclusion criteria: Signing a written consent form; Age 18-75 years; Moderate COVID-19 Exclusion criteria: History of hospitalization due to COVID-19; Participate in any other clinical trial of COVID-19 treatment; Patients under mechanical ventilation at baseline; Sensitivity to atazanavir; Active cancer; Immune system compromised; Abnormal baseline ECG; Pregnancy and lactation; Renal failure; Severe liver failure; multi-organ failure; Concomitant use of CYP3A4 inducers Intervention groups: In group A, 400 mg of hydroxychloroquine on the first day and Kaletra 2 tablets every 12 hours for 5 days, and in group B, hydroxychloroquine 400 mg single dose on the first day and atazanavir/ritonavir daily were administered for at least 5 days. Main outcome variables: Primary Outcome: Recovery within 10 days of starting treatment Secondary outcomes: Improvement within 14 days after starting treatment; Survival rate; Number of days hospitalized; Number of days of intubated; Number of days in the ICU