CD38 is a multifunctional enzyme that can act as a NADase, generate cyclic adenosine diphosphate-ribose (cADPR) – a key Ca2+-mobilizing second messenger – and transport cADPR into cells. There have only been a small number of studies on the functions of CD38 in the central nervous system. In this study, we applied CD38 small interfering RNA (siRNA) to determine the effects of decreased CD38 on the intracellular ATP levels and survival of C6 glioma cells. Our study showed that both CD38 siRNA and 8-bromo-cADPR – a ryanodine receptor antagonist – can lead to a significant increase in the intracellular ATP levels of C6 glioma cells. We further found that the siRNA-induced CD38 reductions can induce decreases in the number of surviving cells. Our study has also suggested that P2X receptors contribute toward the CD38 siRNA-induced decreases in the cell survival. In summary, our study has provided novel evidence suggesting that CD38 mediates both the intracellular ATP levels and the survival of C6 glioma cells, suggesting that CD38 may become a therapeutic target for gliomas.