Nanocomposite of poly(vinyl alcohol) (PVA)-Ag2S was prepared using the hydrothermal process by the in situ reaction with CS2 as the sulfur source. The use of CS2 as the sulfur source can avoid the introduction of the by-products such as NaCl and KCI obtained when Na2S and K2S are used. X-ray diffraction results showed that pure phase of Ag2S was obtained in the prepared nanocomposites. They also showed that the crystallinity of PVA was largely decreased after the composition with nano-sized sulfides. This is also confirmed by infrared spectroscopy. Scanning electron microscopy showed that the Ag2S particles were in sphere shape with 80-120 nm diameter in the as-prepared nanocomposites. Ultraviolet-visible spectroscopy was also used to characterize the as-prepared nanocomposites.