Objective:To implore the effect of continuous positive airway pressure (CPAP) therapy on dizziness patients and its mechanism. Method:Seventy-five dizziness patients were enrolled. All patients accepted polysomnographic test, dizziness handicap inventory, Pitsburgh sleep quality index and Epworth sleepiness scale before and after CPAP therapy. Patients were divided into two groups according to a polysomnographic test: OSAHS group (AHI≥15) and without OSAHS group (AHI<15); divided into three groups according to dizziness handicap inventory score: mild dizziness group (0P<0.01). ②The effectiveness of CPAP therapy between OSAHS group and without OSAHS group has no difference (P>0.05), but CPAP therapy could ameliorate sleep disorder of the OSAHS group. ③Different levels of dizziness had no impact on improving DHI during CPAP therapy. However, the effect on sleep improvement decreased when patients had heavier dizziness. ④Treating by CPAP after three months could significantly improve patients dizziness (P<0.01). ⑤The dizziness of the patients in younger old group and old group have significant improvement after CPAP therapy (P<0.01). However, only younger old group has better sleep. Conclusion:CPAP therapy could dramatically improve dizziness in patients with sleep disorders.