Radiation-induced lung injury (RILI) is the most common complication of the radiotherapy for thoracic tumor. It can lower the ratio of local control and seriously affect the patients' quality of life. At present, the clinical management of RILI is not more than the use of glucocorticoid and anti-inflammatory agent for symptomatic treatments. These treatments do not have any preventive effect but cause much side reactions. In this paper, we review the data from the contigency researches on the mechanism of RILI, from the researches on gene therapy and stem cell-therapy, and we dicuss the more safe, more stable and more efficacious treatment of RILI.