Abstract: Obstructive sleepapnea syndrome (OSAS) is a disease that the pharyngeal portioncollapses repeatedly during sleep and finally results in thecessation of breathing. As the incidence of OSAS rises and thequality of life is highly evaluated, this disease has aroused moreand more attentions among researchers with different backgrounds.After the brief introduction of symptoms, risks and diagnosiscriterions of OSAS, the potential factors that may cause OSAS arediscussed from two main aspects: anatomical structure and nervecontrol mechanism. Then the control mechanism of pharyngealcollapse was discussed from the mechanical point of view. Thebiomechanical models of OSAS are classified into two major types,namely lumped parameter and distributed parameter models. Finally,the advantages and disadvantages of these two types of models arediscussed.