Chloroquine is a long-established prescription drug that is often used clinically to treat malaria and connective tissue diseases. Since December 2019, COVID-19 （corona virus disease 2019） outbreaks caused by SARS-CoV-2 （severe acute respiratory syndrome coronavirus 2） has occurred in China and many countries around the world. Due to the lack of drugs against COVID-19, the disease spreads rapidly and the mortality rate is relatively high. Therefore, specific drugs against SARS-CoV-2 need to be quickly screened. The antimalarial drug Chloroquine phosphate which has already been approved is confirmed to have an anti-SARS-CoV-2 effect and has been included in diagnostic and therapeutic guidelines. However, awareness of the risk of chloroquine phosphate causing acute poisoning or even death should be strengthened. The dosage used according to current clinical recommended dosage and course of treatment are larger than that of previous treatment of malaria. Many provinces have required close clinical monitoring of adverse reactions. This paper reviews the pharmacological effects, poisoning and toxicological mechanisms, in vivo metabolism and distribution, and forensic issues of chloroquine drugs, in order to provide help to forensic practice and clinical work.