Aim: To observe the structure and function changes in lung tissue of rats after head injury in 24 hours. Methods: The experiment was conducted at animal laboratory of Beijing Neurosurgery Research Institute between September 2004 and January 2005. Totally 52 male SD rats were divided into control group (n=10) and head injury group (n=42). The rat models of diffused and closed head injury were made by free falling of a 60 g thing from 100 cm height. Fourteen rats were selected at 6 and 24 hours after injury, respectively for tissue transmission electron microscope observation and blood gas analysis to measure the albumin of bronchoalveolar lavage fluid, ratios of lung and brain wet/dry and lung and brain tissue pathology and compare with the indexes of rats died in 1 minute after injury. Results: All the 52 rats were involved in the result analysis, 14 rats died in 1 minute after injury with the mortality of 33.3%. 1 Albumin of BALF and lung wet/dry ratio of rats died in 1 minute after injury were higher than that of the control group, 6 and 24 hours head injury group [(1.33±1.02), (0.10±0.07), (0.24±0.16), (0.18±0.12) g/L; 5.64±0.74, 4.44±0.09, 4.59±0.16, 4.91±0.19] and the pathology score of the died rats was obviously increased. 2 There was no difference in pH value, standard bicarbonate radical and head wet/dry ratio between the head injury groups and control group. Conclusion: Animal models of neurogenic pulmonary edema can be successfully established by 6 000 g • cm impact. In 24 hours after head injury, blood gas analysis, lung wet/dry ratio and pathologic changes of lung aggravate.