Nanoplate gamma-Bi2MoO6 is prepared by hydrothermal method. Using this material as photocatalyst, rhodamine B and methylene blue were efficiently degraded under visible light irradiation. The degradation kinetics, total organic carbon changes, and electron spin resonance detection of active oxygen species were investigated to clarify the degradation process. The experimental results indicated that the target dyes could be facilely bleached and mineralized. The formation of active oxygen species of (OH)-O-center dot and O-2 center dot is detected, and they are proposed to be responsible for the degradation of the target dyes. The gamma-Bi2MoO6 catalyst is very stable and can be reused. (C) 2009 Published by Elsevier B.V.