Abstract: The knowledge of dielectric properties of ilmenite ore for welding electrode is essential for widening the sources of raw materials in the production of electrode and the development of microwave reduction ilmenite. The dielectric properties of ilmenite with different TiO₂ content (37 %~47 %) at 2.45 GHz at the temperatures from 20 ℃ up to 80 ℃ are measured using the technology of open-ended coaxial sensor method. The temperature increase characteristics of ilmenite is measured by the microwave heating method. The results show that dielectric constant, loss factor and loss tangent of the ilmenite increase significantly with increasing temperature. Dielectric properties of ilmenite enhance with the increasing of TiO₂ content overall. The penetration depth of ilmenite decreases with the increase of temperature ranging from 40 ℃ to 80 ℃, and the best thickness of microwave heating ilmenite is 3~6 cm. The temperature rising curve of ilmenite ore under microwave radiation displays a nonlinear relationship between the temperature (T) and microwave heating time (t).