Three types of crust exist in the area studied. There was an assembled continent at the end of the Hercynian-Indosinian cycle. Since the Cenozoic the area has shown a trend of tension, thinning and oceanization in varying degrees, which is manifested in the creeping and obduction of the Asian continent as well as the spreeding and subduction of West Pacific Ocean, thus bringing about the continental rifts, maginal basins and arc-thrence systems in this area.Geotectonic cycle usually begins with a tensional phase and ends with a compressional phase. When tension predominates, various rifts can be formed on the continental crust and the crust is in the trend of oceanization. When compression predominates, the rifts disappears, the crust is in the trend of continentization and, in the end, folded mountain belts and geosutures can be formed. Thus, the crust is tending towards “maturatity” and thickening. There was an assembled continent at the end of the Hercynian-Indosinian cycle. Since the Cenozoic the area has shown a trend of tension, thinning and oceanization in varying degrees, which is manifested in the creeping and obduction of the Asian continent as well as the spreeding and subduction of the West Pacific Ocean, thus bringing about the continental rifts, maginal basins and arc-thrence systems in this area. Geotectonic cycles usually begins with a tensional phase and ends with a compressional phase When tension predominates, various rifts can be formed on the continental crust and the crust is in the trend of oceanization. The compression predominates, the rifts disappears, the crust is in the trend of continentization and, in the end, folded mountain belts and Thus, the crust is tending towards “maturatity ” and thickening.