Two kinds of nanocomposites of nitrile-butadiene rubber (NBR), zinc methacrylate (ZDMA) and organomontmorillonite (OMMT), NBR-ZDMA-HMMT and NBR-ZDMA-USMMT were prepared by the reactive mixing intercalation method with ZDMA and two kinds of organomontmorillonite, hexadecyltrimethylammonium bromide modified montmorillonite (HMMT) and unsaturated chemical modified montmorillonite (USMMT). The structure and properties of the nanocomposites were investigated by X-ray diffraction, transmission electron microscopy, differential scanning calorimetry and determination of crosslinking density and mechanical properties. The results showed that the interlayer galleries of HMMT and USMMT were enlarged as ZDMA polymerized in situ in rubber matrix and between the interlayer of the silicates. The layered silicates were dispersed disorderly in rubber matrix at a nanometer level. The crosslinking density of the NBR vulcanizates was increased by the addition of ZDMA and HMMT or USMMT The glass transition temperatures of the NBR-ZDMA-OMMT nanocomposites were higher than that of the neat NBR. The mechanical properties of the NBR-ZDMA-HMMT and NBR-ZDMA-USMMT nanocomposites are remarkably superior to those of the neat NBR vulcanizate.