HgMnTe is a typical Mn-based II--VI narrow-gap semimagnetic semiconductor and has been successfully applied in infrared photonic devices. Meanwhile, due to the existence of Mn ions, there are two important magnetic interactions in HgMnTe material. They are d-d and sp--d magnetic inter- actions. These two magnetic interactions make the HgMnTe material have some special photoelectric and magnetic properties such as spin-glass transition, giant negative magnetoresistance, magnetically driven insulator-to-metal, giant Faraday rotation, photoinduced magnetization and magnetic polaron effects. Hence, the HgMnTe material has many potential applications such as magnetic optoelectronic devices, quantum computation and quantum communication and may be a promising candidate material for spintronics.