Abstract: A floating interval method is proposed for topologyoptimization problems of continuum structures. The major idea of thepresent approach is to consider the structure to be optimized as a piece ofbone, whose growing process is controlled by an floating interval ofreference strain energy density, i.e., the update of each material point inthe design domain is determined by its current strain energy density and thereference interval. The update of the reference interval is determined bythe active constraint of the optimization problem. Two numerical examples aregiven to show the validity of the present approach.