Nitraria tangutorum is a widely distributed shrub in the Jilantai Salt Lake at the southwest edge of Ulan Buh Desert. Due to their role in increasing soil fertility, nebkhas (coppice dunes) are regarded as important components of arid land ecosystems. Yet, despite their frequent occurrence, little information exists regarding their dust fall effect and influence range. We investigated the grain size distribution around N. tangutorum at a small scale (within 10 m) according to four wind directions and analyzed the spatial heterogeneity of particles. The amount of non-erodible particles (>0.85 mm) increased with distance from the shrub. The amount of erodible (<0.45 mm) and semi-erodible particles (0.45–0.85 mm) showed an opposite trend, indicating that the shrubs have a protective effect. The dominant particles around the shrubs were non-erodible due to long term accelerated wind erosion and subsequent removal of fine particles.