REE change regularly in the ductile shear zone. Along with intensifying deformation, the contents of all the rare earth elements and the total contents of the LREE, HREE and REE increase, but their REE patterns remain unchanged. Isorat analysis of granitic tectonic rocks before and after deformation shows that the REE compositional variation mainly from REE relative enrichment caused by large volume deficiency. According to the functional relation between the compositional variation and the volume deficiency, the volume deficiency (14. 5%) of mylonite is obtained, and the volume deficiency factor of ultramylonite reaches 20%.