In this report, we have fabricated a novel nanomaterial, titanium dioxide whiskers (TiO2Whs), and evaluate its photodynamic characters on Rhodamine B, where TiO2Whs exhibit better photocatalytic activity than titanium dioxide nanoparticles (TiO2NPs). After testing the biocompatibility, we further investigated the effects of TiO2Whs on human hepatocarcinoma cells (SMMC-7721 cells) under UV illumination from cell level, concentration-dependent effect level, time-dependent effect level, and finally genomic apoptosis level. Our results showed that TiO2Whs possess more obviously photo-killing effect on cancer cells compared with that of TiO2NPs. These studies implied that the novel nanomaterial, TiO2Whs, could be utilized as a promising biomedical agent and would have enormous potential application in photodynamic therapy for cancer treatment in the future.