Abstract: The mordenite was synthesized by magadiite conversion in the presence of diethanolamine（DEA）.The as-obtained mordenite was characterized by X-ray powder diffraction，scanning electron microscopy，and infrared spectroscopy.The pure and well crystallized mordenite which had prismatic shape was prepared.The as-synthesized mordenite was stable towards strong acid because the structure still retained when the product stirred in 6 mol/L HCl for 3 h.The influences of key reaction parameters including the alkalinity and reactant time on the formation of mordenite were examined.The optimized composition of the reactant was obtained.The magadiite would be converted to ANA with high alkalinity and magadiite still existed in the low alkalinity.When the reaction time was 24 h，magadiite could be not converted to mordenite completely.Meanwhile， the products were ANA and NaP when the reaction time was 7 d.

Key words: mordenite, conversion, magadiite, diethanolamine