Due to the devastating consequences of strong earthquakes, the identification of any reliable precursor signatures is of paramount importance. There are many anomalies before strong earthquakes like underground water level, air temperature variations, linear cloud anomalies, total electron content anomalies, local (in situ) anomalies of space plasma parameters (concentrations of ions and electrons, ion and electron temperatures, mass compositions and concentrations of the major ions), extraordinary extremely low-frequency (ELF) and VLF emissions measured onboard a satellite, quasi-constant magnetic and electrostatic fields, extraordinary particle precipitation fluxes for different energy bands and so on. But before using these precursors to predict earthquakes, it is essential to understand the coupling mechanism among geology, atmosphere and ionosphere before strong earthquakes. Therefore, the special issue “Coupling among Geology, Atmosphere and Ionosphere before Strong Earthquakes” is mainly aimed at the research about precursors before earthquakes (especially for strong earthquakes), and the coupling among geology, atmosphere, and ionosphere.