SnS2 nanobelts were successfully synthesized through a controllable solution-phase hydrothermal method on a large scale. The nanobelts have a very high yield, which is more than 95%, with widths ranging from 100 to 200 nanometers, lengths up to several micrometers and thicknesses ca. 10 nanometers. X-ray diffraction patterns, electronic diffraction, X-ray photoelectron spectra, field emission scanning electron microscopy images, transmission electron microscopy images and high-resolution transmission electron microscopy investigated the phase structures, compositions, and morphologies of SnS2 nanobelts. Dodecanethiol played important roles in the process of SnS2 nanobelts formation and growth. The formation mechanism of SnS2 nanobelts was investigated and discussed on the basis of the experimental results.