The photo-catalytic degradation of Congo red (CR) was examined in presence of visible light at various operating condition, pH and amount of catalyst and time. The CR dye degradation rate was 97% about 80 minute of exposure, respectively, indicating that pH 7 was the optimal pH for degradation. The photo degradation processes of dyes were considered to be connected to a kinetic models, which was later shown incorrect. The effective degradation process might be used to explain the degradation of congo red dye.