The floorplan area optimization problem is to determine the shape and dimensions of all the modules when the topology of the floorplan is given. The objective is to minimize the area of the resulting floorplan. Existing methods only apply to slicing floorplans. We present in this paper an algorithm for general hierarchical floorplans. Our algorithm combines the curve-adding technique used in the case of slicing floorplans and a new technique that computes shape curves by iterative modification of the shape and dimensions of individual modules. We also present an optimal points selection algorithm using the technique of dynamic programming to further enhance the process of shape curves construction.