Abstract: Chloroquine is a quinine derivative which is synthesized by German scholars in 1934. In addition to its anti-malaria, treatment of systemic lupus erythematosus and immunomodulatory effects, chloroquine is also found valuable in broad-spectrum antiviral treatment. Clinical trials have confirmed that chloroquine has a good effect on acquired immunodeficiency syndrome. In 2019, there were many patients infected with novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2). Preliminary clinical trials showed that chloroquine had obvious curative effect on patients with SARS-CoV-2. We summarize the effects of chloroquine to different viruses, explain its mechanism, and compare the results of its experiments in vitro and in vivo. The antiviral effect of chloroquine in vivo and in vitro are not consistent, which may be related to the model of animal, dosage and distribution of chloroquine in vivo, and the design of clinical research.