Convective initiation (CI) means the beginning of severe convective weather activities. The study of CI mechanisms is a critical and difficult problem of mesoscale meteorology, and is critical to improve the scientific knowledge of the evolution of local sudden severe convection and the nowcasting of severe convective weather. In this paper, the research results of surfacebased CI mechanisms and elevated CI mechanisms at home and abroad are summarized. Surfacebased CIs are usually triggered by boundary layer convergence lines. In addition, temperature and humidity disturbance, instability, misocyclone, vertical shear, topography and other factors also have a certain impact on the time and position of surfacebased CIs. Atmospheric instability is sensitive to the change of local temperature, especially humidity, and has a great influence on CI. The interaction of ambient vertical wind shear and thermonamic field of boundary, the feedback between vertical velocity and vorticity of misocyclone, and the thermodynamic effects caused by topography all can influence the surfacebased CIs. Most elevated CIs are related to the bores, gravity waves and lowlevel jets. The lowlevel jets transport water vapor upward and northward, reducing the stability of the environment, and the shear associated with the lowlevel jets can also produce updraft, which is important for nocturnal elevated CI. Convectively generated gravity waves and bores are conducive to the elevated CI, which can lift the lower atmosphere and reduce the stability. Elevated convergence and weak but persistent mesoscale lifting also help to increase the possibility of elevated CI. This article can be used for reference in the CIreleated research and the prediction and early warning of localized sudden severe convection.