The Stratosphere-Troposphere Exchange (STE) refers to atmospheric mass exchange between stratosphere and troposphere in both directions, including Stratosphere-to-Troposphere Transport (STT) and Troposphere-to-Stratosphere Transport (TST). STE has important impacts on atmospheric chemical composition and radiative equilibrium. Therefore, it is very important to investigate STE activities for further advancement in atmospheric chemistry, climate change, and stratosphere troposphere coupling in atmospheric models. In this paper, we review major STE processes in observations, simulations, diagnoses, and mechanisms, and compare their difference either on methods or on models. Although many synoptic-scale STE studies have been conducted, STE events in meso and micro-scales remain to be further investigated, especially in physic mechanism, observations and simulations. It attracts more and more attention on stratospheric influences of troposphere pollutant transport, especially on the impacts resulting from the meso and micro-scales strong convection weather events. With the rapid global urbanization in the global, it is very essential to investigate the TST events under the background with strong convection activities over heavy air polluted metropolitan areas.