Ultrasonic　phased　array　technique　was　applied　to　characterize　the　orientation　angle　of　the　crack-like　defects　in　simulation　and　experiment.　The　total　focusing　image　was　generated　first　using　the　full　matrix　capture　data　obtained　from　the　linear　ultrasound　array　to　determine　the　location　of　the　defect.　Then,　scattering　coefficient　distribution　was　deduced　to　extract　the　information　on　the　defect　orientation　by　dividing　the　linear　array　into　a　certain　number　of　subarrays.　Besides,　the　influence　of　subarrays　parameters　setting　and　the　inspection　location　of　phased　array　transducer　was　studied.　Principal　component　analysis　(PCA)　was　used　to　evaluate　the　influence　of　subarrays　parameters　setting　on　the　crack-like　defects　orientation　characterization,　such　as　element　number　in　one　subarray　and　element　number　between　adjacent　subarrays,　and　the　best　parameters　were　obtained　by　evaluation　indicators　extracted　from　scattering　coefficient　distribution,　namely　measuring　error,　angular　resolution　and　relative　width　of　the　ridge.　Results　in　simulation　and　experiment　show　that　the　crack　orientation　angle　can　be　measured　accurately　in　the　conditions　of　optimal　subarrays　parameters　setting,　11　elements　in　every　subarray　and　1　element　between　adjacent　subarrays,　and　the　error　is　less　than　2%　by　the　approach　of　crack-like　defects　orientation　characterization　based　on　scattering　coefficient　distribution.　©　2016　Acta　Acustica.