The　noninvasive　estimation　of　tissue　temperature　and　state　is　a　key　problem　in　hyperthermia.　The　purpose　of　this　paper　is　to　study　a　kind　of　new　ultrasonic　method　for　hyperthermia　monitoring　in　clinic;　it　is　a　noninvasive　method　based　on　ultrasonic　tissue　characterization　of　B-mode.　The　experiments　were　carried　out　on　in-vitro　animal　tissues　that　were　heated　by　hot　water　and　microwave　coagulation,　and　a　series　of　B-mode　ultrasonic　images　of　liver　were　obtained　over　the　temperature.　Then　the　images　were　processed　to　extract　some　character　parameters　at　different　temperatures,　and　the　temperature　correlations　of　these　ultrasonic　tissue　character　parameters　were　calculated.　It　has　been　found　that　some　parameters　varied　in　accordance　with　the　temperature　changes　in　the　heated　tissue,　and　the　average　gray　value　in　B-mode　ultrasonic　images　of　the　heated　liver　has　linear　relation　with　the　temperature.　©　2007　IEEE.