In December 2019, a novel coronavirus was detected in pneumonia patients which was later named 2019-nCoV. Since the first human coronavirus detected in the 1960s, 2019-nCoV is the seventh coronavirus that is known to infect humans [1]. Among all the human coronaviruses, four of them, including NL-63, 229E, HKU1 and OC43, cause mild illness, while the other three, SARS-CoV, MERS-CoV and 2019-nCoV, lead to serious disease [2]. To characterize the new pathogen causing acute infection in humans, researchers have conducted urgent studies on the 2019-nCoV, from its epidemiology and clinical medicine to etiology and virology. This review focuses on the epidemiology and clinical manifestations of 2019-nCoV, the diagnosis and treatment of infected patients, and in particular, evidence regarding the origin of 2019-nCoV.