Abstract: Hexagonal MoS₂ nano-grade particles of 20⁶0 nm in diameter have been synthesized in a CTAB/toluene/n-butanol/water W/O reverse microemulsion with(NH₄)₂MoS₄ as a precursor of molybdenum and NH₂OH·HCl as a reducing agent.The effects of synthetic parameters such as acidity,ω₀ and annealing temperature on the formation of MoS₂ samples were investigated.TEM images showed that acidity and ω₀ play important roles in the size of MoS₂ nano-grade particles.XRD patterns revealed that MoS₂ nano-grade particles,annealed at 700℃ for 2 h under a flow of N₂ atmosphere,had high crystallinity with well-stacked layered structure.UV-vis absorption spectra suggested that the onset of the MoS₂ nano-grade particles is of significant blue-shift compared to that of bulk MoS₂.