The novel coronavirus pneumonia (COVID-19) has been well controlled in China. Most of the COVID-19 patients were having postinflammatory pulmonary fibrosis (PPF) on the follow-up CT scan when discharged, and complaining about exertional dyspnea of different levels, presenting with an UIP (usual interstitial pneumonia) pattern or NSIP (non-specific interstitial pneumonia) pattern on the CT scans. Will the PPF get improved or stay stable, or progress? Such questions could only be answered by follow-up and monitoring of the pulmonary function. At the same time, we should learn from the lessons on pulmonary function loss of the SARS patients and MERS patients, some of whom had persistent impaired lung function after discharge. Pirfenidone and Nintedanib had been approved for the treatment of idiopathic pulmonary fibrosis(IPF), showing effectiveness on non-IPF pulmonary fibrosis as well. However, there are no studies about the application on PPF resulting from viral pneumonia. Given the follow-up status of SARS patients and MERS patients, and the PPF of COVID-19 patients, we should be careful about the discharged patients with a close follow-up, and further studies on PPF of COVID-19 are needed.