Abstract: Gneissic granitic rocks of the Huangling formation in western Guangdong are the basement metamorphic series (2600Ma～1700 Ma). Three different structural styles are developed in these rocks: penetrating shear zone in the lower part, regular affine deformation zone in the middle part, and corrugation deformation zone in the upper part. Strain analysis shows that different structural styles are produced by the approximate horizonta1 shearing and its continuous upward migration. Chemical analysis reveals that gneissic granitic rocks possess the characteristics of crustal reformed S-type granite. In fact, these gneissic granitic rocks are resulted groin autochthonous or near autochthonous shearing anatexis, whose protoliths arc neritic- hypoabyssal clasolites. The depth of shearing anatexis is above l3km～ 15km, and the peak of shear deformation occurred on 2000Ma～ 1700Ma.