Microwave　ablation　(MA)　is　popular　as　a　minimally　invasive,　painless　and　effective　oncological　treatment.　The　paper　presents　an　approach　of　characterizing　the　thermal　coagulation　during　microwave　ablation　using　B-mode　ultrasound　image　textures　and　pattern　recognition　technique.　During　the　MA　treatment,　the　series　of　B-mode　ultrasound　images　were　obtained.　Textures　of　different　ROIs　such　as　gray　level　histogram　and　gray　level　co-occurrence　matrices　from　the　obtained　ultrasound　images　were　extracted　separately.　And　then　these　textures　were　classified　by　support　vectors　machine　(SVM).　The　experimental　results　have　shown　that　the　textures　of　coagulated　and　non-coagulated　region　have　significant　differences.　The　classification　accuracy　of　SVM　by　19　parameters　is　0.9528.　The　method　described　in　this　paper　is　an　effective　way　to　realize　thermal　coagulation　monitoring　using　texture　features　of　B-mode　ultrasound　images.　©2009　IEEE.