In a method for surface-modifying a neural electrode, a neural electrode array is formed, first and second metal nanoparticles having different solubilities with respect to an etching solution are simultaneously electrode-deposited on a surface of the neural electrode array, and the second metal nanoparticles are selectively etched using the etching solution, thereby forming a porous structure including the first metal nanoparticles on the surface of the neural electrode array.