Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Methods Totally 100 young male army members newly recruited from Sichuan province （400 meters above sea level） were enrolled. They were randomly divided into two groups: 50 in aminophylline group （A group） and 50 in control group （C group）. A group and C group orally took aminophylline and placebo respectively for 10 days

7 days before entering Lhasa （3 658 meters above sea level） by air and 3 days after it. Several parameters were measured at three time points: before drug taken

7 days after drug taken

and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide （NO）

superoxide dismutase （SOD）

catalase （CAT）

hydrogen dioxide （H2O2）

lactic acid （LA）

as well as arterial oxygen saturation （SO2）

arterial oxygen partial pressure （PaO2）

and arterial carbon dioxide partial pressure （PaCO2）. Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude

the serum levels of SOD

CAT

H2O2

LA

PaCO2 increased in both groups

yet to a much larger degree in C group than A group （P<0.01）; and NO

SO2

PaO2 decreased more markedly in C group （P<0.05 for NO

P<0.0001 for SO2 and PaO2）. Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude.