OBJECTIVE： To systematically review the effect of CYP2C19 genetic polymorphism on lansoprazole pharmacokinetics， and provide evidence-based reference for clinical individualized medication of lansoprazole. METHODS： Retrieved from PubMed， EMBase， Web of science， Cochrane Library and CJFD， retrospective studies about the effect of CYP2C19 genetic polymorphism on lansoprazole pharmacokinetics were collected， Meta-analysis was performed by Rev Man 5.2 software after data extract and quality evaluation. RESULTS： Totally 11 retrospective studies were included， involving 200 patients. The gene type included homozygote express metabolizers （EM）， heterozygous express metabolizers （HEM） and slow metabolizers （PM）. Results of Meta-analysis showed CYP2C19 polymorphism significantly affected cmax， AUC， t1/2， tmax and CL/F. The cmax and AUC in group PM were higher than group HEM and group EM； CL/F in group EM was higher than group HEM and group PM； t1/2 in group PM was higher than group HEM and group EM， while there was no significant difference in the t1/2 between group HEM and group EM； tmax in HEM and group PM were higher than group EM， while there was no significant difference in the tmax between group PM and group HEM. CONCLUSIONS： CYP2C19 genetic polymorphism shows obvious effect on lansoprazole pharmacokinetics， which is the key factor for causing efficacy of lansoprazole and individual differences among adverse reactions， and clinic should take into account individualized dose regimen of lansoprazole.