1. The relationship of the action of diphosgene upon different parts of the respiratory sys- tem to the hemodynamic changes caused by the gas was studied.

2. The earliest disorder is emphysema after phosgene or diphosgene inhalation.

3. Trichloromethyl carbonate is a kind of new chemical raw material, It may substitute for phosgene and diphosgene in chemical synthese.

4. According to the results of the observation, the authors believe that diphosgene poisoning may cause typical pathological changes of ARDS.

5. These results led us to conclude that the responses caused by diphosgene on URT may be of the effect to reduce the degrees of pulmonary edema.

6. Scanning electron microscope and transmissional electron microscope were used to observe the ultrastructural changes of respiratory tract in rabbits inhaling low concentration of diphosgene.

7. The triphosgene, being as the substitute for phosgene and diphosgene in synthesis, is not only low-toxic but also safe and convenient to use with mild conditions, good selectivity and high yields.