The emission of electromagnetic wave is a fundamental property of any substance at a temperature higher than 0 K. However, the capability of thermal radiation is not an immutable property of materials, and the static and dynamic modulations of thermal emission are realized by different methods in recent years. This review represented the general principles of thermal emission, and recent work on the static and dynamic modulation of infrared thermal emission by using nanophotonic structures. Besides, the emerging applications of spectrally modulated selective infrared emitters in fields such as energy were highlighted. In addition, this review also summarizedthe current problems and outlined the potential future direction in the modulation of infrared emission of inorganic materials.