Abstract: Standardized design is used for the steam generator lateral supports of a nuclear power plant. The types of the supports are various, including plate-type and shell-type supports, and linear-type support, and bolting and welded joints are also used, which makes the mechanical calculation and evaluation more complicate. Finite element analysis software is used to calculate the steam generator upper and lower lateral supports under level-D load case, then ASME ⅢNF and appendix F is used to evaluate all the types of supports. The key points of the mechanical calculation and evaluation of the SG supports are proposed.