This　paper　presents　a　method　for　detecting　contour-based　optical　flow　field　of　the　heart　in　ultrasound　B-Scan　images,　which　is　Matching　Algorithm　of　Boundary　Cluster　Centers.　The　heart　being　a　deformable　body,　this　paper,　as　a　result,　is　a　research　on　the　optical　flow　field　of　deformable　body,　which　is　of　common　concern　in　the　research　of　optical　flow　field.　This　being　our　first　research,　we　intend　to　simplify　our　target,　i.e.　we　do　not　attempt　to　research　on　all　pixels　of　the　heart　image,　but　rather　our　focus　studies　on　some　boundary　cluster　centers　that　can　represent　the　motional　condition　of　the　heart.　First,　we　obtain　the　boundary　cluster　centers　of　every　frame.　Second,　we　match　the　centers　of　the　two　neighboring　frames　according　to　the　matching　tactics　of　common　motion　and　obtain　the　watching　difference　of　every　cluster　center　(δSi)　i=1,2...,　which　is,　then,　divided　by　the　interval　time　of　neighboring　frames(δt),　i.e.　δSi/δt=Vi　(i=1,　2...).　In　this　way　we　obtain　the　optical　flow　field.　The　above　tactics　are　the　bases　of　the　matching　operation.　If　the　tactics　are　correct,　there　will　be　a　more　accurate　way　to　detect　the　optical　flow　field　of　a　deformable　body.　The　paper　also　shows　some　estimated　results　of　B-Scan　contour-based　optical　flow　field　by　applying　the　method　of　matching　algorithm　of　boundary　cluster　centers.