Abstract: Nonlinear interaction of high-power electromagnetic waves and magnetized plasmas produces a plethora of fundamental phenomena that can be exploited for powerful diagnostics of the earth’s ionospheric plasma. To establish a unified theory of magnetized stimulated electromagnetic emissions (SEEs) in space, we summarize possible parametric decay instabilities in magnetized plasmas. Then, we review the most recent progress of stimulated electromagnetic emissions during ionospheric modification experiments for the past decades. Important associated phenomena with SEEs are detailed outlined, including artificial ionization layer, multiple-scales plasma irregularities, wave-particle and wave-wave interaction mechanism, and low frequency EM wave generation. Finally, challenges and future will be discussed.