The photodegradation of crystal violet (CV) was studied by nitrogen doped reduced-graphene oxide (N-rGO)/ZnO nanorod nanocomposites. ZnO nanorods and N-rGOs were synthesized by hydrothermal method separately. N-rGOs were dropped on the ZnO nanorods via spin coater for synthesizing the nanocomposites. The X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM) images revealed that ZnO nanorods are synthesized well. The photodegradation results showed that the 80% degradation of CV obtained after 120 min illumination of the best nanocomposite under 40W visible light.