Abstract: The effects on physiology and oxygen inversive diffusion following the rapid decompression at high altitudes,with various oxygen-rich supplies before decompression simulating the range of gas from the molecular sieve oxygen generating system(MSOGS)were observed. The results demonstrated that while the oxygen content was lower than 60%, the hypoxia sign appeared within 10s after hypoxia expose. There was a physiological equivalent range in 6～8s after decompression when it was beyond 70%. The oxygen inversion diffusion after decompression had two processes, which was associated with the time of useful consciousness and physiological effects.

Key words: absorbents, hypoxia, alveoli