NaA zeolite with average particle size of 1 μm was successfully synthesized by microwave heating. Influences of pre-crystallization time, microwave power and microwave heating time on the synthesis of NaA zeolite were investigated. The as-synthesized sample was characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) and particle size distribution (PSD). Thermal and flame retardant properties as intumescent flame retardant (IFR) in chloroprene rubber (CR) system, such as thermogravimetry (TG), limiting oxygen index (LOI), burning rate (BR) and specific extinction area (SEA) were further investigated by adding NaA zeolite particles to CR. Experimental results show that the thermal stability and LOI value increased while BR and SEA decreased by adding 5 phr NaA zeolite into the 40 phr IFR filled CR system.