ObjectiveTo systematically review the prevalence of obstructive sleep apnea syndrome (OSAS) in China. MethodsPubMed, EMbase, The Cochrane Library, CBM, CNKI, WanFang Data, and VIP databases were electronically searched to collect cross-sectional studies of the prevalence of OSAS in China from inception to October 30th, 2020. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of included studies. Meta-analysis was then performed using Stata 16.0 software. ResultsA total of 27 studies were included, with a total sample size of 97 746 cases and 10 853 confirmed OSAS patients. Meta-analysis results showed that the prevalence of OSAS in China was 11% (95%CI 5% to 17%), of which females was 12% (95%CI 5% to 19%) and males was 12% (95%CI 5% to 20%). OSAS cases grouped by regions were as follows: Central China 4% (95%CI 2.7% to 4.5%), South China 5% (95%CI 2.7% to 6.7%), North China 7% (95%CI 4.6% to 9.3%), Northeast China 22% (95%CI 17.7% to 61.2%), Southwest China 4% (95%CI 3.2% to 5%), Northwest China 16% (95%CI 14.5% to 17.7%), and East China 17% (95%CI 2.8% to 30.6%). OSAS patients grouped by ages were as follows: 4% (95%CI 3% to 5%) for ≤14 years old, 5% (95%CI 2% to 7%) for 15-44 years old, 13% (95%CI 6% to 20%) for 45-59 years old, 16% (95%CI 6% to 25%) for 60-74 years old, 13% (95%CI 4% to 23%) for 75-89 years old, and 11% (95%CI 2% to 21%) for ≥ 90 years old. A subgroup analysis based on the year of publication found that the prevalence of OSAS fluctuated between 6% and 9% from 2005 to 2020, and the prevalence was the highest from 2000 to 2005 accouted with 21% (95%CI 0.8% to 40.5%). ConclusionsThe prevalence of OSAS in China is relatively high, and there are differences in the prevalence among individuals of different ages and regions. The 60-year-old groups in addition to the Northeast and East China regions have a high incidence. The prevalence of OSAS is substantially consistent between males and females. Due to the limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusions.