A nanocomposite consisted of Ag nanoparticles and WS nanosheets was prepared by a two-step procedure, in which Ag sol was generated at first, then added into WS nanosheet dispersion to form the nanocomposite via self-assembly. The nanocomposites with different content of Ag nanoparticles were successfully prepared. The results show that Ag nanoparticles with the diameter of 10-20 nm are uniformly distributed on WS nanosheets and not oxidized. All nanocomposites are mesoporous. The specific surface area and the mesoporosity of WS are improved due to the existence of Ag nanoparticles. The specific capacitance of the nanocomposite increases with the increasing content of Ag nanoparticles. The 2000 cycles of charging and discharging were carried out on 20%AgNPs@WS nanocomposite, proving its good cycling performance. It has smaller transfer resistance and internal series resistance than WS nanosheets. This nanocomposite has potential application in supercapacitors. [ABSTRACT FROM AUTHOR]