Objective: To investigate the antihistamine-releasing effect of a peptide isolated from wasp venom of Vespa orientalis. Methods: This peptide was separated from crude venom by chromatography methods and mass spectrometry. Then various concentrations (2, 4, 8, 16, 32, 64, 128 and 256 μmol/L) of the peptide were incubated with mast cells and lactate dehydrogenase assay was performed. Results: No significant effect was observed in lactate dehydrogenase absorbance under 128 μmol/L concentration. This implied that the peptide did not cause cell death in mast cells and consequently, histamine release did not happen. Moreover, the results showed the IC