Early childhood caries (ECC) is the most common chronic disease in young children. Its reported prevalence varies greatly across China. This systematic review aimed to explore the epidemiological characteristics of ECC in mainland China from 1987 to 2013. In total, 102 articles were included. The pooled national prevalence and care index (ft/dmft%) for ECC were 65.5% and 3.6%, respectively. The overall ECC prevalence declined from 77.9% during 1987-1994 to 56.4% during 2010-2013. The pooled ECC prevalence for children aged 1-6 years was 0.3%, 17.3%, 40.2%, 54.4%, 66.1%, and 70.7%, respectively. There was no significant difference in prevalence between boys (59.1%) and girls (58.9%); and the care index was also similar (8.1% versus 7.7%). Slightly higher ECC prevalence was observed in rural areas (63.5%) compared with urban areas (59.5%) (RR = 1.08, 95% CI: 1.02-1.14); but a much higher care index was reported in urban children (6.0%) than their rural counterparts (1.6%) (RR = 3.68, 95% CI: 2.54-5.35). The 2006-2013 map of ECC prevalence among 5-year-olds showed wide geographic variations across China. Four adjacent provinces, including Sichuan, Chongqing, Hubei, and Shaanxi, constituted the areas with the lowest ECC prevalence in mainland China.