In the present study, two temperate sandy beaches, which were located on the coast of different seas with different hydrological states, were selected to investigate the variations and drivers of the taxonomic structure and functional traits of the free-living marine nematode. According to the present study, Xyalidae and Chromadoridae were widely observed in both locations, but the species composition and functional traits were not completely the same. In fine sands, non-selective deposit feeders or colonizers (nematodes with c-p = 2) were far more quantitatively than other functional traits, suggesting a relatively restricted range of functional traits. The increased microhabitat heterogeneity in coarse sands can support species with more diverse functional traits. Chl-a was the most prominent variable that significantly related to nematode species composition and functional traits at XB sites. Nematode data were closely related to temperature or temperature-related environmental factors, such as DO and salinity, at GB sites.