The invention relates to a sealing seat and a sealing ball. The sealing seat comprises a shell body and a bearing piece contained in the shell body and connected with the shell body. A bearing face facing an upstream position is constructed on the bearing piece, inclines in the axial direction and has the diameter gradually decreased from the upstream position to a downstream position. The bearing face can make sealed contact with the surface of the sealing ball. Downhole pressure keeping-down can be conducted effectively by using the sealing ball and the sealing seat, and accordingly the basis and security are provided for using of a downhole tool.