Abstract: Natural rubber/tungsten composites based on natural rubber and micro-/submicro-sized tungsten particles were prepared to use for X-ray shielding.The microstructure,curing characteristics,static mechanical properties,dynamic mechanical properties and X-ray shielding performance of the composites were systematically investigated.The results indicate that the tungsten powders homogeneously distributed in the rubber matrix and influenced the curing process of the compositions.The temperature of compounds should be kept below 115 ℃ during the extrusion process.In consideration of curing rate and reversion,145 ℃ was necessary for curing process.The damage and deformation resistances of the composites were obviously enhanced because of the reinforcing effect of submicro-sized tungsten particles.The glass transition temperature of the composites was not influenced by the change of the tungsten particle size and loading.Higher loading and finer size of tungsten particles lengthened the zigzag reflection path and transmission distance and hence improved the X-ray shielding performance of the composites.