With the assistance of diethylenetriamine(DETA), well-crystalline PbSe cuboidal structures with different concave faces in each plane have been successfully prepared through a hydrothermal process using Na2SeO3 as selenium source at 180 °C for 48 h. The products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy and luminescence spectroscopy. The field emission scanning electron microscopy showed that the edge lengths of these cuboidal crystals ranged from 1.5 to 2.5 µm, and the edges of a cube crystal extend outwards from its core with a tiny cubic center leaving step-like faces. The shape evolution of PbSe crystal from eight-dendritic structure to cuboidal structure was observed and the possible growth mechanism was proposed. Results revealed that the temperature played a crucial role in the final morphology of PbSe microstructures, and other factors such as the solvent composition and the molar ratio of metal/chalcogen were also discussed. The photoluminescence (PL) spectrum of as-prepared PbSe crystals shows the photoluminescence emission spectrum consists of a main intense peak at 435 nm and a shoulder at 420 nm. This synthesis method could be extended to the morphogenesis of other inorganic crystals with complex forms.