The REE content of tectonic rocks in the shear zone shows regular variation in the deformation process. When the intensity of deformation becomes stronger, the contents of various rare earth elements and the contents of LREE, HREE and REE increase obviously, but the REE patterns remain unchanged. Through equal ratio analysis of granitic tectonic rocks before and after deformation in Jiaonan orogenic belt, the authors have reached the conclusion that the variation of REE results mainly from volume deficiency. According to the function relation be- tween composition variation and volume deficiency, it is known that when granite changes into mylonite the volume deficiency ratio is 14.5%, and when granite changes into ultramylonite the volume deficiency ratio is 20%.