Objective: To examine the efficacy and safety of adjunctive memantine for patients with schizophrenia receiving antipsychotic treatment.Methods: The randomized,double-blind,placebo-controlled trials(RCT) comparing memantine and placebo for patients with schizophrenia published as of July 9,2017 in Chinese were searched from the databases of CNKI,CBM,Wanfang Data Knowledge Service Platform and those in English were searched from PubMed,EMBase,PsycINFO,Cochrane Library by two researchers separately.And relevant printed RCT published during the same period were searched.RCTs screening,data extraction as well as quality assessment were conducted by the two researchers separately.Clinical efficacy,cognitive function,rate of discontinuation and adverse drug reactions were analyzed using RevMan 5.3 software.Results: Nine RCTs with 512 patients(treatment group:n=259;placebo group:n=253) were included.Meta-analyses of total psychopathology 〔SMD=-0.56,95%CI(-1.01,-0.11),P=0.02〕 and negative symptom score 〔SMD=-0.80,95%CI(-1.24,-0.36),P=0.000 4〕 showed the superiority of memantine over placebo,but there was no significant difference between positive symptom score 〔SMD=-0.20,95%CI(-0.48,0.08),P=0.16〕 and general psychopathology scores 〔SMD=-0.27,95%CI(-0.64,0.10),P=0.15〕 of the two groups.Furthermore,meta-analysis of cognitive function assessment showed the superiority of memantine over placebo 〔WMD=3.09,95%CI(1.77,4.42),P<0.000 01〕.Similar rates of discontinuation 〔RR=1.34,95%CI(0.76,2.37),P=0.31〕 and adverse drug reactions were found between the two groups(P>0.05).Conclusion: This meta-analysis suggests that adjunctive memantine appears to be effective and safe in improving total psychopathology,negative symptom score and neurocognitive function.However,its long-term efficacy and safety are warranted to confirm these findings.