The lung is one of the most sensitive organ to radiotherapy. The thoracic radiation can produce dramatic effects, both early and late. In order to value the effects of radiation on lung, a lot of efforts have been made by researchers. This paper summarized the recent progresses in experimental investigations on pulmonary radiationdamage, including physiological, biological, phathological and cellular changes. In addition, main view on mechanism of pulmonary radiation damage were also involved.