Abstract: Objective To establish a sleep apnea syndrome (SAS) model in rats. Methods Fifty male SPF Sprague-Dawlev rats were randomly divided into five groups: normal control group (NC)， 2-week and 4-week experimental control groups (2C and 4C)，and 2-week and 4-week intermittent hypoxia groups (2H and 4H). The rats of 2H and 4H groups were laid in the hypoxic cabin for 8h per day，in which nitrogen and oxygen were input circularly (90s/cycle). The Fi02max was 21%± 0.5% and Fi02min 9% ± 1.5%. The gas concentration and the cyclic time were automatically controlled. The rats of 2C and 4C groups were in the normoxic cabin, NC group in room air. At the experimental end points，the right ventricle flmctions (RVEDP, RVESP，RV ± dp/df max), the mean pulmonary arterial pressure (mPAP), the mean carotid arterial pressure(mCAP)，the weight ratio of left ventricle plus septum to body [(LV+S)/WT] and of right ventricle to left ventricle plus septum [RV/(LV+S)] were measured, respectively. Results The mPAPs of 211 group and 4H group were much higher than those of 2C group and 4C group? respectively (P＜ 0.05). The RV+dp/dt, RV-dp/dt and RVESP in 4H group were significantly higher than those of 4C and 2H groups(P＜ 0.01). The mCAP，RV/(LV+S) and (LV+S)/WT among all of the groups were no significantly different (P＞ 0.05). Conclusion The sleep apnea syndrome SPF rat model can be successfully established with the method by which operation is convenient, control is precise，repeatability is well and the effects is well consistent with the SAS pathophysiology.

Key words: Sleep apnea syndrome, Rat, Hypoxia, Model