Abstract: PbS nanocrystals with different precursor molar of S2-/Pb2+ were prepared in alcohols medium from water-solubility precursors. The crystal structure, average particle size, morphology and luminescence properties of as-synthesized products were characterized by X-ray diffraction (XRD) spectra, transmission electron microscope (TEM) images, ultraviolet-visible (UV-VIS) absorption spectra and photoluminescence (PL) spectra. The XRD patterns show that the average particle size of the samples is calculated to be increased from 3.9 nm to 5.9 nm with the S2-/Pb2+ molar ratio enhanced. The PL emission peak position is red-shifted from 1 009 nm to 1 486 nm. The influence of different S2-/Pb2+ molar ratios on growth rate of PbS nanocrystals was discussed and the growth mechanism was thought to be the diffusion-controlled growth model via Ostwald ripening.