Corona virus disease 2019 (COVID-19) was caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The phenomenon of positive real time reverse transcription polymerase chain reaction (RT-PCR) result of SARS-CoV-2 in recovered patients had occurred and the research about these patients was rare. In our study, we did a retrospective review of medical records from COVID-19 patients admitted to one ward of Tongji Hospital of Hua Zhong University of Science and Technology from 10 February to 13 April 2020. From 10 February to 13 April 2020, there were 108 patients of COVID-19 admitted in the one ward of Tongji Hospital. Among them, eight cases were readmission patients because the RT-PCR result of SARS-CoV-2 was positive again after discharge. On the second admission, they had no symptoms and their chest computed tomography was almost normal. Data from laboratory tests of the readmission patients showed that all eight patients had normal white blood cell count, lymphocyte count. The inflammatory factors like procalcitonin and interleukin 6 were normal. After treatment, two patients met the standard and were discharged. The other six patients were still in the hospital because their RT-PCR of SARS-CoV-2 did not get three consecutive negative results and the course of two patients had persisted more than 90 days. We still needed to be alert that these patients could infect other people as a source of infection, and we also needed to be alert that these patients become chronic virus carriers. It also aroused our concern about the discharge standard of COVID-19.