Abstract: The removal of hydrogen cyanide(HCN) using magnesium oxide(MgO)at various temperatures was investigated in the presented paper. The solid products were analysed by X-Ray Diffraction. The effects of temperature, mass fraction of MgO, initial volume fraction of HCN and residence time were discussed. The kinetic parameters of the reaction between HCN and MgO were obtained. Results show that MgO remarkably reacts with HCN through transforming the nitrogen in HCN into the solid product MgCN₂ from 873 K. The removal efficiency of HCN increases with the increase of temperature, mass fraction of MgO and residual time in linear relation; but decreases with the initial volume fraction of HCN in negative power function relationship. The reaction order and apparent activation energy of the reaction between HCN and MgO are 0.72 and 32.2 kJ/mol respectively.