Objective: To systematically review the prevalence of dental caries from 1980 to 2018 to provide evidence for caries prevention in mainland China. Methods: Four databases were selected with online search tools to offer maximum coverage of the published literature on the provincial or national level of caries prevalence: Medline, EMBASE, China National Knowledge Infrastructure (CNKI, in Chinese) and Wanfang databases (in Chinese). We supplemented the results with relevant publications from the government health sectors, textbooks and web-based databases. Studies published between 1 January 1980 and 26 March 2018 were included. The quality of literature was assessed, and a meta-analysis was conducted using Stata12.0. Results: A total of 82 studies were included in the final analysis. There were 1.49 million samples retrieved from 1980 to 2018, and the overall pooled prevalence of caries was 52.0% (95% CI: 49.4%-54.6%) in mainland China. The overall prevalence of caries increased from 36.4% (95% CI: 31.5%-41.5%) in the 1980s to 51.8% (95% CI: 34.9%-68.7%) in the 1990s, stabilised at 50.7% (95% CI: 43.8%-57.6%) in the 2000s and slightly increased to 53.1% (95% CI: 50.8%-55.5%) in the 2010s. The pooled caries prevalence was 64.8% (95% CI: 61.7%-67.8%), 47.3% (95% CI: 43.1%-51.5%), 42.4% (95% CI: 38.3%-46.5%), 66.7% (95% CI: 50.8%-82.6%) and 82.0% (95% CI: 72.5%-91.4%) for the ages/age groups 5, 12, 15, 35-44 and 65-74, respectively. The average dental caries pooled prevalence in urban areas was 51.4% (95% CI: 48.5%-54.2%), which was lower than 54.6% (95% CI: 47.9%-61.4%) in rural areas. Conclusion: The prevalence of dental caries in mainland China is generally high, and an increasing trend was observed over the past 38 years. The prevalence of dental caries in mainland China varied geographically, and its characteristics differed over time. Regional disparities between eastern/western China and rural/urban areas still exist. Comprehensive local prevalence data on caries are summarised here for the first time, which provide valuable evidence for the oral disease burden in China. Keywords: dental caries, prevalence, systematic review, China