Background: Epidemiologic studies have yielded inconsistent findings between breastfeeding and risk of early childhood caries(ECC).Objective: We performed a meta-analysis to summarize available evidence from cohort,case-control,and cross-sectional studies of the association between feeding pattern and breastfeeding duration and ECC risk from published observational studies.Design: Studies were identified by searching PubMed,Embase,ISI Web of Science,and the Cochrane Library from 1990 to 2015 August and by reviewing the reference lists of pertinent articles.Random-effects models were used to estimate pooled odds ratios(Ors)using STATA 12.0.Results: 34 studies(9 birth cohorts studies,4 case-control studies and 21 cross-sectional studies)consisting of 64315 children were included.Pooled results from 21 studies found no significant association for ever breastfeeding and ECC compared with never breastfeeding(OR: 0.80; 95%CI: 0.62-1.02,P =0.069)with high evidence of heterogeneity(I2 =85.8%,P<0.001).However,subgroup analysis only found ever breastfeeding could decrease the risk of ECC in the studies of 3-6 years old children(OR= 0.74,95%CI: 0.57-0.98,P =0.034),NOS ≥6(OR =0.66,95%CI: 0.44-0.99,P=0.043),sample size more than 500 subjects(OR=0.67,95%CI:0.47-0.94,P =0.021),published after 2010(OR = 0.47,95%CI:0.25-0.86,P =0.015).Pooled analysis from 15 studies shown that breastfeeding longer than 12 months could increase the risk of ECC compared with breastfeeding shorter than 12 months(OR= 1.91,95%CI: 1.41-2.59,P <0.001)with high evidence of heterogeneity(I2 = 89.9%,P<0.001).Conclusions: Results of this meta-analysis suggest that ever breastfeeding may protect against ECC,and breast-feeding duration longer than 12 months is associated with higher risks of ECC.Additional research is needed to estimate the effect after adjusting for other possible confounding factors.