PURPOSE: To produce a zirconia-pillared clay having high crystallinity, inter-layer spacing and substantially high thermal stability.

CONSTITUTION: This preparing method for the zirconia-pillared clay comprises the following steps: (a) mixing a clay selected from the group consisting of smectic clays and fluoromicas with a soln. of zirconyl acetate for a time and at a temp. sufficient to form a pillared clay product, (b) separating the pillared clay product formed from the soln., (c) washing the separated pillared clay product with water, (d) drying the separated and, washed pillared clay product at a temp. from about 50 to 200°C, (e) calcining the dried pillared clay product at a temp. from about 300 to 700°C.