The feasibility study for the application of the photoelectrocatalytic decolorization of Rhodamine B (RhB) was performed in the photoelectrochemical reactor with immobilized TiO₂ particle. The effects of operating conditions, such as current, electrolyte and pH were evaluated. The experimental results showed that optimum TiO₂ dosage and current in photoelectrocatalytic process were 83.3 g/l and 0.5 A, respectively. It was found that the RhB could be degraded more efficiently by this photoelectrocatalytic process than the sum of the two individual oxidation processes (photocatalytic and electrolytic process). The addition of NaCl increased the initial decolorization rate and reduced reaction time and optimum dosage of NaCl was 0.15 g/l. The decolorization rate of photoelectrocatalytic process increased sharply with the decrease of pH value. However when the NaCl was added the, pH effect was not high.