Aim: A systematic review and meta-analysis was designed to evaluate the efficacy and safety of Bifidobacterium for preventing necrotizing enterocolitis (NEC) in preterm infants. Methods: We searched the Cochrane Library, PubMed, EMBASE and Web of Science to December 2017. Risk ratio (RR) with 95% confidence intervals (CIs) were estimated to compare the outcomes of the groups. For the pooled RR estimating the incidence of NEC, we also performed subgroup analysis. Besides, sensitivity analysis was performed to examine the stability of the combined results. Two reviewers assessed trial quality and extracted data independently. The work has been reported in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR (Assessing the methodological quality of systematic reviews) Guidelines. All statistical analyses were performed using standard statistical procedures provided in Review Manager 5.2. Results: Twenty four randomized, placebo-controlled studies (N = 6155 participants) were included in this analysis, of which twenty two studies were used for assessing the efficacy of Bifidobacterium for preventing NEC and seventeen for assessing the safety (sepsis and death). When comparing Bifidobacterium groups with control groups, the relative risk of developing NEC (RR 0.38, 95% CI 0.25-0.58; P < 0.00001) or death (RR 0.74, 95% CI 0.60-0.92; P = 0.006) was significantly lower in the Bifidobacterium groups. No significant difference in the incidence of sepsis was found (RR 0.87, 95% CI 0.73-1.03; P = 0.11). In addition, significant results for NEC were also found in all subgroups we made. Conclusions: Bifidobacterium may have a beneficial effect and be safe in preventing necrotizing enterocolitis in preterm infants.