NaX molecular sieve films on ceramic paper prepared by in-situ hydrothermal method were investigated. The NaX zeolite seed crystals of a uniform size of 5 mu m were synthesized by hydrothermal method in a mother solution having a composition of 3.5Na(2)O : Al2O3 : 2.1 SiO2 : 500 similar to 1000 H2O. These dip-coated NaX seed crystal on ceramic paper lead to further the thickness (20 similar to 100 mu m) of NaX film on the substrate at 90 degrees C for longer 3 similar to 7 days in autoclave. Pure zeolite films consisting of a continuous intergrown of 5 similar to 20 mu m NaX crystal have been prepared on the substrates. The zeolite films were characterized by XRD, SEM, BET and XRF.