| The NCEP/NCAR global troposphere 1°×1°reanalysis grid data have been employed toselect ten landfall typhoon cases in north-western Pacific in order to diagnose formative processof Typhoon's warm-center structure from troposphere low layer to troposphere mid-high layerand the relationship between structure of warm-center and evolution of intensity during its wholelife period. Results show that structures between typhoon's temperature field and its vorticityfield have different characters clearly from troposphere low layer to troposphere mid-high layerduring each life-phase: (1)Warm-center structure of typhoon has been formed from up to downand been stronger than ever when it develops increase, and structure of warm-center establishedat 300 hPa at first; while typhoon collapses quickly after it landfall, its structure of warm-centerhas been died away from down to up, and the speed of collapse is slower than other layers, that isto say, warm-center structure of typhoon is the clearest at 300hPa. (2) There is a correspondingrelation clearly between typhoon's intensity, and its warm-center structure: From tropospherelow layer to troposphere mid-high layer in vertical, when closed warm-center grows up abouttyphoon center, and closes to its positive vortex-center bit by bit, ultimately when two centersalmost coincide with each other, typhoon developments continually so as to mature,here itsintensity has been the strongest; when the distance from warm-center to positive vortex-centerlargens and closed warm-center disappears bit by bit, its intensity dies away, which is to say, thedistance from the warm-center to the positive vortex-center is anti-correlated with the intensity oftyphoon; if the distance becomes shorter, the intensity of typhoon becomes much stronger. (3)when the distance from the warm-center to the positive vortex-center is less than 100kin steadilyin each layer, the intensity of typhoon is the strongest, and typhoon has come to mature phase.
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