Shape optimization analyzing methods according to aspects of the present invention are analysis methods for optimizing part of a structure model using plane elements or three-dimensional elements. The methods include a design-space defining step of defining a portion of the structure model that is to be optimized as a design space, an optimization-block-model generating step of generating an optimization block model in the defined design space, the optimization block model being formed of three-dimensional elements and analyzed for optimization, a coupling step of coupling the generated optimization block model with the structure model, and an analyzing step of performing analysis in accordance with input of an analytic condition to calculate an optimal shape of the optimization block model.