One-dimensional CdS nanocrystallites were used as precursors for preparation of mesoporous CdS nanorods through an ion-exchange process at room temperature. The results from x-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive x-ray analysis, and x-ray powder diffraction techniques showed that Ag+ did not affect the electronic structure of CdS or cause the disorder of crystal structure although the product contained a considerable amount of Ag2S. The visible absorption of Ag2S nanoparticles in the mesoporous structure led to the result that the intensities of Raman scattering peaks of the mesoporous nanorods were weaker than those of CdS initial nanorods.