Abstract: To build up a steady and credible animal model of obstructive sleep apnea syndrome(OSAS)． MethodsSodium Hyaluronate was injected into the palatoglossal arch， palatopharyngeal arch and root of the tongue of eight Wistar rats. An electroencephalogram, electromyogram and oronasal airflow were recorded by PSG before and 4 weeks after injection when rats were under light anesthesia, which was expected to be similar to the sleep state. ResultsWhen the animals were under light anesthesia, the electroencephalogram and electromyogram were similar to the sleep state. All animals showed apnea with unusual movements of the thorax and the abdomen before and 4 weeks after injections. Differences between apnea index(AI) and the longest apnea before and after injection of Sodium Hyaluronate was obvious(P＜0.05). ConclusionAn animal model of OSAS in rats established by injection of Sodium Hyaluronate was steady, credible and similar to OSAS of human beings. It can be used to study the pathogenesis, pathological and physiological changes, and complication of OSAS.