Titanium dioxide(TiO₂) photocatalysts have attracted great attention as a material for photocatalytic sterilization in the food and environmental industry. The aim of this study was to design a new photocatalytic reactor and its application to sterilize Vibrio parahaemolyticus. The photocatalytic reaction was carried out with various flow rate of cell suspension and ultraviolet(UV)-A illumination time. In the bactericidal efficiency of photocatalytic reactor on V. parahaemolyticus, it was confirmed that UV-A illumination time and flow rate affected the cell killing activity. After 60 min UV-A illumination, killing activity of V. parahaemolyticus was more than 99.9 %.