Objective　To investigate the establishment of rabbit model of obstructive sleep apnea syndrome (OSAS) through hypobaric hypoxia and their changes in pathophysiology. 　Methods　Twelve adult rabbits were randomly assigned to 2 groups

control group and experimental group. The rabbits of experimental group were placed in hypobaric hypoxia cabin

in which the altitude was 5 000 m

10 h daily

for 4 weeks. The rabbits of

control group were raised normally. The airway were scanned by CT

arterial blood gas was analyzed and respiratory airflow was monitored. The rabbits were sacrificed after the experiment

and pharyngeal tissue and genioglossus were harvested for pathological examination. 　Results　In hyoid bone plane of upper airway

the pharyngeal of experimental group showed  significant thickened (P0.01)

the anteroposterior diameter (P0.01) and cross-sectional area (P0.05) had significant decreased compared with that of the control group. In middle of soft palate plane

the soft palate of experimental group were significant thickened

the anteroposterior diameter were significant decreased compared with that of the control group (P0.05). While sleeping monitoring

apnea hypopnea index (AHI) of experimental group was more than control group (P0.01). The breathing rate (P0.01)

expiratory/inspiratory (P0.01) and mean respiratory depth (P0.05) were significantly different in the groups. Arterial oxygen pressure [P(O

2

)

]

of experimental group was degraded (P0.05)

and partial pressure of carbon dioxide in arterial blood [P(CO

2

)

]

was significant elevated (P0.05) compared with that of the control group. In pathological examination

control group had the mucosa of pharynx was covered by stratified squamous epithelium

glandular organ was thin

and the genioglossus was arranged closely. In experiment group

the pharyngeal epithelium was cornified and proliferated

with proliferation of glandular organ

but the genioglossus was collapsed. 　Conclusion　The hypobaric hypoxia condition can be used to produce rabbit model of OSAS. The physiology and the pathology of rabbit models were similar to the changes in OSAS patients.