Star-shaped US patterns, which were composed of rod-like nanoparticles with diameters of 4-7 nm and lengths ranging from 150 to 200 mu, were successfully prepared by a convenient microemulsion technique at room temperature. It was found that the hydrophobic carbon chain of surfactant played an important role in controlling the morphology of the product. The present convenient microemulsion method is relatively mild and low toxic. It may provide a new route to the production of other metal sulfide patterns at room temperature.