The effect of inorganic modified admixture on the performance of zeolite humidity controlling materials was studied experimentally. The humidity controlling mechanism of the zeolite humidity controlling materials was investigated based on the analysis of scanning electron microscope(SEM) and the theory of moisture absorption/desorption of materials. The results show that the compressive strength, the softening coefficient and the humidity controlling performance of the zeolite humidity controlling materials are better when the content(by mass) of inorganic modified admixture is 15%20%. The modified admixture can react with zeolite to form C S H gel and hydrated aluminate products. The surface physical and chemical adsorption of water in the air and the capillary effect of the zeolite humidity controlling materials makes the zeolite humidity controlling materials be able to regulate the humidity automatically.