In　order　to　utilize　high-performance　XML　tree　pattern　query　(TPQ)　for　implementing　of　XQuery　language　effectively,　it　is　necessary　to　analysis　the　query　plan　and　identify　tree　pattern　from　it.　In　this　paper,　we　extend　the　functional　intermediate　language　FXQL,　which　is　used　to　implement　XQuery　language,　with　an　extended　XML　generalized　tree　pattern　representation　(GTP++).　Then,　we　propose　an　XML　tree　pattern　identification　approach,　which　is　composed　of　a　suit　of　query　expression　rewriting　rules　for　extracting　tree　pattern　and　a　GTP++　construction　algorithm.　Based　on　this　approach,　both　explicit　and　implied　propositional　logic,　various　structural　constraints　and　predicates　can　be　extracted　across　nested　query　blocks　in　XQuery　FLWOR　expressions.　The　tree　pattern　identified　by　this　approach　is　more　holistic　and　precisely　than　previous　methods.　The　approach　expands　the　application　of　XML　tree　pattern　query　technology　in　the　implementation　of　XQuery　language.　Experiments　show　its　effectiveness　and　practicability.