Objective : Herb medicines are potential sources of useful edible and medicinal plants. They are used as a drug because of their various biological activities such as immunomodulatory, antiviral, and antitumor functions. Nelumbo nucifera have been applied in Chinese herbal prescriptions to improve tissue inflammation. However, it has not been elucidated on the effect of the flower of Nelumbo nucifera in cells. Method : In the present study, to examine the effect of that on glioma cells, U87, the essential oil was extracted from the flower of Nelumbo nucifera (NN essential oil). U87 cells were exposed to different concentrations of 2-40 ug/ml of NN essential oil in ethanol. Cell viability was measured by MTT assay at 24 h. To find out the intracellular target signal molecule(s) for this antiproliferative activity of NN essential oil, phosphorylation of Akt, ERM, MAPK or p38 proteins were examined by Western blot analysis. To study long term effect of NN essential oil in U87 cells, the image of cells treated with NN essential oil for 4 days were obtained. Results and Conclusion : NN essential oil was shown to exhibit antitumor activity in glioma cells, at a broad range of concentrations of 10-40 ug/ml. The phosphorylation of Akt and Endoplasmic Reticulum Matrix (ERM) proteins which known to be involved in the cell death, were gradually decreased to 2 hours after addition 20 ug/ml of NN essential oil. However, the phosphorylation of mitogen-activated protein (MAPK) and p38 was found to increase in NN essential oil treated cells. NN essential oil treated cells showed decreased glioma cell number. These results provide a possible NN essential oil-induced inhibitory signal for tumor cell proliferation that is initiated by the decrease in Akt activity. Moreover, it is likely that the activation of p38 is required for the NN essential oil-induced inhibition of tumor proliferation.