Dry and wet grinding effects of kaolinite on the formation of zeolite Na-A and Na-X in NaOH solution are fundamentally investigated. Intensive dry grinding causes the structural deformation of kaolinite into an amorphous state with enhanced chemical reactivity. The degree of the activated state of kaolinite particles is mainly dependent on the grinding time and the activated particles easily react with NaOH to form zeolite Na-A and Na-X according to the degree of activation. The further wet grinding of the activated particles and NaOH can promote the formation of zeolite Na-X and it can be deduced that wet grinding alters the Si/Al ratio of kaolinite particles by a mechanochemical effect during prolonged wet grinding.