Abstract: In the research of integrating high level synthe sis （HLS） and floorplan,the astringency of design space searching algorithms can not be assured because floorplan and HLS are mutual input and output. In this paper,a “bridge” is constructed between the representation of HLS and floorplan,and the searching space of integrating HLS and floorplan can be represented by a single representation.Based on this new representation,the astringency of simulated annealing algorithm on this design space is analyzed.