Abstract: Different hypoxia exposure of various degrees has different impact on individuals. In order to investigate the changes of cardiopulmonary function in healthy subjects after exposure to acute intermittent hypoxia (AIH), we conducted a prospective, randomized, crossover-controlled study was conducted. Ten healthy subjects were randomly assigned to AIH, acute continuous hypoxia and normoxia, respectively. The cardiopulmonary function [heart rate, blood pressure, pulse blood oxygenation (SpO 2) and lung function] were monitored throughout the whole intervention. Following each intervention, lung function and overnight sleep-respiratory monitoring were performed. Our results showed that AIH exposure at a certain intensity had no obvious adverse effects on cardiopulmonary function and was safe for healthy subjects.