The aim of this study is to utilize photothermal therapy (PTT) to treat urothelial cancer using the unique optical properties- surface plasmon resonance of gold nanoparticles (GNPs). The GNPs were conjugated with anti-EGFR and anti- MUC7 antibody for tumor targeting. The conjugated GNPs were exposed under a green light laser (532nm) to produce the enough thermal energy and to kill the transitional cell carcinomas (TCC). Our results show that the cancer cells (MBT2, T24, 9202, 8301) were damaged at relatively lower energy (10 W/cm 2, 1.6 Hz with 300 ms) compared with the group without added GNPs. The damage was directly related to the applied laser energy and irradiation time. The therapeutic effects of superficial disease in situ by intravesical GNP agents instillation will be further performed in animal study of C3H mice. It is expected that the mini-invasive technology of PPT with GNPs not only reduces the high recurrence of TCC but also avoids the side effects from traditional chemotherapy.