Importance: No clinically proven effective antiviral strategy exist for the emerging epidemic Coronavirus Disease 2019 (COVID-19). Objective: To compare the efficacy and safety of favipiravir and arbidol to treat COVID-19 patients. Design: Prospective, multicenter, open-label, randomized superiority trial in February, 2020. Setting: Multicenter study. Participants: Patients with confirmed COVID-19 admitted to 3 hospitals from Feb. 20, 2020 to Mar. 12, 2020. Interventions: Conventional therapy + favipiravir or arbidol. Main Outcomes and Measures: The primary outcome was clinical recovery rate of day 7. Duration of fever, cough relief latency, and auxiliary oxygen therapy or noninvasive mechanical ventilation rate were the secondary outcomes. The patients with chest CT imaging and laboratory-confirmed COVID-19 infection, aged 18 years or older were randomly assigned to receive favipiravir or arbidol. Safety data were collected for further follow-up for a week. Results: 120 patients were assigned to favipiravir group (116 assessed) and 120 to arbidol group (120 assessed). In full analysis set (FAS) cohort, clinical recovery rate of day 7 does not significantly differ between the favipiravir group (61.20% (71/116)) and the arbidol group (51.67% (62/120)) (P=0.1396, OR: 1.47). The latency to fever reduction and cough relief in favipiravir group was significantly shorter than that in arbidol group (both P<0.0001). No statistical difference was observed of auxiliary oxygen therapy or noninvasive mechanical ventilation rate (both P>0.05). The most frequently observed favipiravir-associated adverse events were abnormal LFT (10/116, 8.62%, OR: 0.86, P=0.7156), psychiatric symptom reactions (5/116, 4.31%, OR: 5.17, P=0.1149), digestive tract reactions (16/116, 13.79%, OR: 0.97, P=0.6239) and raised serum uric acid (16/116, 13.79%, OR: 5.52, P=0.0014). Conclusions and Relevance: Among patients with confirmed COVID-19, favipiravir, compared to arbidol, did not significantly improve the clinically recovery rate by 7 days. Favipiravir significantly improved time-to-relief for fever and cough. Antiviral-associated adverse effects associated with favipiravir are mild and manageable. Trial Registration: This study is registered with Chictr.org.cn, number ChiCTR2000030254.