Using the new equation for density of states due to the generalized uncertainty relation, the entropy of Schwarzchildde Sitter spacetime is discussed. By use of the new equation for density of states, it overcomes the shortcoming that on eliminating divergence the calculation of black hole entropy with brickwall pattern needs a cut off. Thus, it gets the result of the direct proportion betwee n black hole entropy and its horizon area, brings to light the relationship between Schwarzchildde Sitter and its cosmos event horizon and makes clear that the black hole entropy is the entropy of quantum state near the event horizon.