TheNorthChinablock,thewesternportionoftheSino-KoreanCraton,isroundedbyYanshanianinthenorthandQinling-Dabieorogenicbeltsinthesouth.Thewidespreaddevelopmentofextensionalbasinsinthisblockindicateshorizontalextensionorcontinuedthinningofapreviouselythickened,trnstablelithospherethroughouttheMesozoic.Inthispaper,weattempttosimulatenumericallythegeodynamicalprocessofthebasinformationbyusingthemountain-basinevolutionsystem.WeassumethattheformationofnumeroussedimentarybasinsintheNorthChinablockistheresultofthecrustalextension,whichdestructsrapidlythepreviouslythickenedcrust.