In recent years, some two-dimensional nanomaterials, such as graphene and molybdenum disulfide, cause extensive interests from scientists due to their excellent performances. In this paper, MoS2 was synthesized by a simple hydrothermal method without any assisted reagents, the MoS2 nanosheets display relatively high photocatalytic activity of p-nitrophenol degradation under visible light illumination (lambda > 420 nm). Some experimental reaction conditions were optimized, the highest degradation efficiency of 55.0% is obtained within 120 min at initial 10.0 mg L-1 p-nitrophenol when the MoS2 is prepared at 200 A degrees C for 20 h with the mole ratio of S/Mo = 1/1. A probable mechanism of photo-degradation was discussed. To our knowledge, there are no other reports on MoS2 photocatalytic degradation of phenolic compounds including p-nitrophenol so far. The present report is expected to contribute toward the disposal of highly toxic pollutant under visible light. [GRAPHICS] .