Objective: To study the expression and switching of Th1/Th2 cytokines gene in human gliomas and its effects on occurring and developing of human gliomas. Methods: Interleukin(IL)-2 and interferon-γ represent Th1 type cytokines. IL-4, IL-6, IL-10, and IL-13 represent Th2 type cytokines. The gene expressions of Th1/Th2 cytokines in human glioma cells, glioma infiltrating lymphocytes, and glioma cell lines were detected by reverse transcription polymerase chain reaction (RT-PCR). The biological activity of cytokines in the supernatant of glioma cell lines was assayed by enzyme-linked immunosorbent assay (ELISA) method. Results: The total positive rates of Th1 and Th2 type cytokines gene in human glioma cells were 14.77% and 75%. The total positive rates of Th1 and Th2 type cytokines gene in glioma infiltrating lymphocytes were 22.73% and 68.17%. There was obviously predominant expression of Th2 type cytokines in human glioma tissues, glioma infiltrating lymphocytes, and glioma cell lines. There was no unbalanced expression of Th1/Th2 cytokines in normal brain tissues. Conclusion: There is a predominant expression of Th2 type cytokines in human glioma cells. The switching of Th1/Th2 cytokines gene may play an important role in the occurring and developing of human gliomas.