In this chapter, we will first introduce the propagation theory of lightning EMPs interaction with the ionosphere on the basis of the full-wave FDTD method. We will then investigate the propagation effect of lightning radiated electromagnetic (EM) fields in the EIWG by considering the effect of the Earth curvature, the effect of the ground conductivity, and the effect of different ionospheric profiles. Finally, we will present applications, including (1) propagation of narrow bipolar events (NBEs) at different distances, (2) lightning electromagnetic fields propagation over mountainous terrain, and (3) the optical emissions of lightning-induced transient luminous events in the nonlinear D-region ionosphere.