Abstract: Nano-sized NaY zeolite was synthesized in-situ hydrothermally with a mixture of amorphous microspheres made by spray drying of Suzhou kaolin clay calcined at different temperature levels.The chemical composition of the microspheres before and after synthesis was determined by X-ray fluorescence analysis（XRF），the crystal structure of the microspheres was characterized by X-ray diffraction spectrum（XRD），and their morphologies were characterized by scanning electron microscopy（SEM）.The influences of the factors，such as amount-of-substance ratio of silica to alumina，dosage of seeding director，alklinity，water consumption，and calcination temperature of kaoline on in-situ crystallization synthesis were investigated，and some problems occurred in the synthesis process were also discussed.Pure nano-sized zeolite NaY microspheres were synthesized.

Key words: in-situ synthesis, NaY zeolite, kaoline, nano structure