The aim of this study is to investigate the role of human cytomegalovirus (HCMV) infection in glioma pathogenesis and its possible mechanism. Based on the previous experiments, the expressions of signal transducer and activator of transcription 3 (STAT3) and endocan in HCMV-infected U87 cells, a human glioma cell line, were detected, and the relationship among HCMV, STAT3 and endocan was analyzed. The results showed that HCMV infection induced the upregulation of endocan mRNA and protein as well as the activated STAT3 in U87 cells. On the other hand, decreased levels of endocan mRNA and protein were observed in U87-STAT3-knockdown cells by RNAi. Furthermore, downregulated levels of endocan mRNA and protein were found in U87 cells treated by ganciclovir, an anti-viral drug. Then the expression of pSTAT3 in 79 glioma specimens and 8 control brain tissues was detected by immunohistochemistry (IHC) and the relationship between pSTAT3 level and glioma grade was analyzed. Compared with the control brain samples, increased level of pSTAT3 was found in glioma specimens and the staining intensity was related to glioma grade. The results suggest that HCMV infection is involved in glioma pathogenesis via upregulating endocan expression through STAT3 signaling pathway, and further provide some new clues for the treatment of glioma.