Objectives: Dengue virus is a type of flavivirus that is transmitted by Aedes mosquitoes.Infection by this virus results in dengue fever, which ranges from asymptomatic or mild symptomatic dengue fever (DF) to severe dengue (SD) like dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).Significant elevations in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and bilirubin (Bil) have shown to be present in a large number of clinical cases infected by dengue virus and are indicators for liver injury provided there are no other combined infections or injury in the liver.Currently, the overall incidence of liver injury caused by dengue infection is not clear.Therefore, this study aims to assess the risk of liver injury, represented by elevated levels of liver enzymes,in the patients infected by dengue virus.Methods: The related original literature was searched in multiple databases, including Medline, Embase, Cochrane Library, Google Scholar and CNKI (China National Knowledge Infrastructure), and Wanfang Databases.The literature was selected through strict inclusion and exclusion criteria, and the quantitative synthesis of the incidence of liver enzyme elevation and the mean levels of the enzymes were performed with R software and IBM SPSS20 for Windows.The fixed or random effects model was employed, according to the results of a statistical test for homogeneity.Results: In total, 34 studies were included the data of which were extracted and weighted.The incidence of AST elevation with 95% confidence interval (95%CI) was 0.80(95%CI:0.56-0.92) in SD patients and 0.79 (95%CI: 0.74-0.83)in DF patients;the incidence of ALT elevation was 0.54(95%CI: 0.34-0.73)in SD patients and 0.55 (95%CI: 0.48-0.62) in DF patients;the incidence of LDH elevation was 0.44(95%CI:0.32-0.58) and the Bil elevation was 0.14 (95%CI: 0.11-0.18) in DF patients.The synthesized mean value of AST and ALT increased sequentially and significantly from the DF, DHF I, DHF II to DSS groups.There were significant differences in the ALT or AST values between the different grades of dengue infections (P <0.01), except for the ALT value in DSS and DHF II.Conclusions: The elevation of liver enzymes is common in dengue infections.In dengue infection, AST elevation occurs with the highest incidence, which is followed by ALT, LDH and Bil.The synthesized mean values of AST/ALT increased sequentially and significantly from DF, DHF I, DHF II to DSS patients and may be used as reference for the stratification of disease severity.The elevations of AST and ALT may be indicators for evaluating liver injury in dengue infection and for clinical diagnosis and treatment.