In the present study, a device for measuring the viscosity and melting temperature of hot metal is designed based on the method of damped torsional oscillations. The effects of carbon, titanium, chromium, vanadium, and sulfur contents on the viscosity and melting temperature of hot metal are investigated. The results indicated that titanium is the most important element affecting the viscosity and melting temperature of hot metal. Carbides of titanium, chromium, and vanadium are precipitated when the hot metal cooled below the melting temperature. This is an important reason that titanium, chromium, and vanadium have great influence on the viscosity and melting temperature of hot metal. Furthermore, the influences of carbon and sulfur contents on the viscosity and melting temperature of hot metal are also analyzed.