Using chitosan and sodium alginate as raw material and 4A zeolite as structural modifier, 4A zeolite/sodium alginate/chitosan composite microspheres were prepared by complex condensation, the composite microspheres were characterized by means of microscope、SEM 、XRD and FTIR. The effect of 4A zeolite on microsphere formation and swelling properties of the composite microspheres was investigated. The results show that the weight and particle size of the composite microspheres increased with the increase of the 4A zeolite addition. 4A zeolite was beneficial to the granulation of Composite Microspheres, The highest rate of granulation reached 98.5%. After freeze-drying, the particle size were uniform, and the sphericity was regulation. Under different pH and temperature conditions, 4A zeolite can effective inhibits the swelling performance of composite microspheres, but the microspheres still maintained pH and temperature sensitivity. 4A zeolite can be used as a structural modifier in drug controlled release system for further research and application.