As a class of semiconductors, metal chalcogenide especially post-transition metal sulfides as semiconducting nanoparticles have been vastly studied, primarily due to their potential use in the areas of non-linear optics, luminescence, electronics, energy storage, catalysis, and so on [1]. Moreover, the band gaps of these nanoparticles are dependent on the particle sizes [2]. As the size of particles become smaller, the ratio of the surface atoms to those in the interior increases that leads to a significant influence on the properties of the material surface [3]. Thin SnS films have a band gap of direct transitions (1.32–1.5 eV) [4] and a band gap of indirect transitions (1–1.3 eV) [5] between those of Si and GaAs. Tin sulfide nanoparticles were successfully synthesized using a thermal decomposition method. SnS nanoparticles have been prepared using SnCl2 as a precursor and without need to high pressure or very high temperature and pH adjusment. Transmission electron microscopy (TEM) analysis demonstrated SnS nanoparticles are spherical and average particles size was between 10-22 nm. Synthesized nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy(TEM), Fourier transform infrared (FT-IR) and Energy-dispersive X-ray spectroscopy(EDAX).