NaX zeolite crystals of 50 mu m were grown by a continuous crystallization with seed crystal (10 mu m) in a mother solution having a 3.5Na(2)O : Al2O3 : 2.1SiO(2) : 1000H(2)O composition. The seed crystal morphology of NaX zeolite shows that an octahedron is formed composed of 8 equilateral triangles which have an average lattice constant of a = 24.9911 angstrom with a SiO2/Al2O3 molar ratio of 2.1 similar to 2.4. In order to grow crystals of zeolite X to an appropriate size by the continuous method, the mother solution was supplied with various seed contents (3 similar to 20 wt%) in an autoclave at 90 degrees C after 7, 12, 16, 19 and 24 days.