Phosgene inhalation can induced pulmonary edema formation. The purpose of this study was to investigate cell of apoptosis in pulmonary edema mice induced by phosgene. Fifty-two BALB/c mice were random divided into a negative group and a positive group with 26 mice in each. Mice were exposed for 5 min to air and phosgene in the negative group and in the positive one, respectively. The dose of phosgene was 539 ppm. After 4 h of exposure, all mice were anesthetized. Lungs were analyzed for lung wet/dry weight ratio and pathological alternation. The method of isolation and culture of alveolar type II cells (ATII cells) was established to observe their apoptosis by electron microscope and flow cytometry. Apoptosis of lung cells was observed by DNA gel electrophoresis and TUNEL. The lung wet/dry weight ratio was significantly higher in the positive group (6.42 +/- 1.00) than in the negative group (4.25 +/- 0.47, p < 0.05). A large amount of fluid effusion was observed in the alveolus of mice induced by phosgene. Alveolar type II cells were identified by tannic acid staining and electron microscope. The apoptotic signs in alveolar type II cells, alveolar type I cells, eosinophils, macrophages, symphocytes, and ciliated cells were viewed under electron microscope in positive group. The ratio of apoptosis cells (40.26 +/- 7.74) in positive was higher than that (1.58 +/- 1.01, p < 0.001) in the negative group by flow cytometry. DNA ladder alternation was seen through DNA gel electrophoresis. Apoptosis of epithelia and vascular endothelia in lung were found by TUNEL. These results indicate that there is success in establishing a model of pulmonary edema and method of isolation and culture of AT II cells in BALB/c mice. Phosgene can induce apoptosis of cells in the lungs of BALB/c mice, and this indicates that pulmonary edema is related to apoptosis of lung cells in mice, induced by phosgene.