We demonstrate low-loss chalcogenide ( ${\mathrm{As}}_2{\mathrm{S}}_3$ ) waveguides on a ${\mathrm{LiNbO}}_3$ substrate for the mid-IR wavelength ( $4.8\mathrm{\mu m}$ ). Designed for single-mode propagation, they are fabricated through photolithography and dry-etching technology and characterized on a mid-IR measurement setup with a quantum cascade laser. For straight waveguides, propagation loss as low as $0.33\mathrm{dB}/\mathrm{cm}$ is measured and low-loss bends on the order of $100\mathrm{\mu m}$ are simulated, with measurement results showing $<3\mathrm{dB}$ for a $250\mathrm{\mu m}$ bend radius. The coupling efficiency is estimated to be 81%. In addition, the influences of variations in width and bend radius are also investigated.