Using palladium chloride (PdCl2) as the palladium precursor, ethanol as reducing agent and cetyltrimethylammonium bromide (CTAB) as a stabilizer and guiding agent, Pd nanoplates were synthesized via photothermally assisted solution approach with visible light from a commercial incandescent lamp as light source. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and UV-visible absorption spectroscopy. The effect of CTAB amount on the growth morphology and size of palladium nanomaterials was also investigated. The electrocatalytic properties of the nano-Pd modified glassy carbon electrode for ethanol oxidation were investigated by cyclic voltammetry. The results indicate that the morphology and size of the Pd nanoparticles can be controlled by adjusting the mole ratios of PdCl2 to CTAB. The polygonal Pd nanoplates with a narrowly distributed size of 46 nm are obtained when the mole ratio of PdCl2 to CTAB is 1:80 and the irradiation time is 6 h, which show the excellent electrocatalytic activity and anti-poisoning faculty for the ethanol oxidation.