Abstract: The eclogite xenoliths and other deep-derived ones are first discovered in a ring pipe of alkali syenite-prophyries in Heqing County,yunnan Province.This suggests the existence of granutite-eclogit facies under the cover of the Yangtze Platform.Either the rocks represented by these xenoliths may be elder than the Early Proterozoic Dahong Shah group,or they may be similar to the Dahong shah group,but suffered higher-rank metamorphism.The alkali-rich porphyries,widely distributing both inside and outside the western margin of the Yangtze Platform,may be of the same origin: their original magma was to derive from somewhere of The crust-mantle boundary,and it was subjected to crust-mautle mixing.Such a process is assumed that with the westward underthrusting of the Yangtze Plate,magma source would gradually deepen westwards,and alkalinitf of original magma would increase in the same direction.