Hierarchical tin oxide(SnO₂) architectures were synthesized with a facile hydrothermal method. In the hydrothermal synthesis, sodium dodecyl benzene sulfonate(SDBS) surfactant plays an important role as struc_x005fture-directing reagent. The synthesized samples were characterized by powder X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM) andhigh-resolution transmission electron microscopy(HRTEM). The results clearly reveal that the hierarchical architectures of SnO₂were composed of aggregated nanosheets with a thickness of about 100 nm. A possible mechanism for the formation of the SnO₂hierarchical architectures was proposed. In addition, the gas sensing properties of the as-prepared products were investigated and it was found that the sensor based on the special SnO₂hierarchical architectures exhibited a high response and good selectivity to NO₂at the optimal working temperature of 160 °C