Some issues with regard to spherical Yin Yang grids are reviewed, such as transformation relationship, advantages and disadvantages, and the data interpolation exchange method in the overlapping boundaries. Also three numerical methods, including the optimized Schwarz method, CIP CSLR advection numerical method, and multi moment finite volume method which has been implemented on the spherical overset Yin Yang grids, are discussed and summarized. For the optimized Schwarz method, the advantages of solving the spherical elliptic problem are discussed from the aspect of the discretization of the shallow water equations. For the CIP CSLR advection numerical method and multi moment finite volume method, the analysis is mainly conducted about how to construct the interpolation functions in the grid cells. The development of the global nonhydrostatic Yin Yang grid model is prospected.