Mulitipe stoichiometric ratio of two-dimensional (2D) transition metal dichalcogenides (TMDCs) attracted considerable interest for their unique chemical and physical properties.Here we developed a chemical vapor deposition (CVD) method to controllably synthesize ultrathin NiS and NiS2 nanoplates.By tuning the growth temperature and the amounts of the sulfur powder,2D non-layered NiS and NiS2 nanoplates can be selectively prepared with the thickness of 2.0 and 7.0 nm,respectively.X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization reveal that the 2D NiS and NiS2 nanoplates are high-quality single crystals in the hexagonal and cubic phase,respectively.Electrical transport studies show that electrical conductivities of the 2D NiS and NiS2 nanoplates are as high as 4.6 × 105 and 6.3 × 105 S·m-1,respectively.The electrical results demonstrate that the synthesized metallic NiS and NiS2 could serve as good electrodes in 2D electronics.