Noninvasive　monitoring　of　hyperthermia　is　important　for　treatment　guidance　and　thermal　dose　control.　One　potential　approach　is　to　monitor　the　change　of　temperature　or　coagulated　zones　through　ultrasonic　backscattered　signal　processing.　In　this　paper,　we　presented　a　noninvasive　method　for　hyperthermia　monitoring　based　on　the　analysis　of　microstructural　characteristics　of　in　vitro　porcine　liver　tissues　at　different　temperature　(20　degrees　C-60　degrees　C)　including　normal　and　coagulated　tissues　by　estimating　the　center　frequency　of　scatterers　(CFS)　using　the　autoregressive　(AR)　cepstrum　of　ultrasonic　backscattered　signals.　The　method　is　based　on　the　discrete　scattering　model　described　in　the　tissue　characterization　literature　and　the　observation　that　most　biological　tissues　are　semi-regular　scattering　lattices.　A　total　of　20　in　vitro　porcine　liver　samples　were　used　and　heated　by　the　water　bath　in　the　experiments.　Experimental　results　show　that　the　CFS　in　porcine　liver　tissues　decreases　as　the　temperature　increases.　The　CFS　obtained　using　this　method　may　be　used　as　a　characteristic　parameter　for　tissue　characterization　in　noninvasive　monitoring　of　hyperthermia.　(C)　2013　The　Authors.　Published　by　Elsevier　B.V.