The J rock body formed in Caledonian period mainly consist of greyish white medium-coarse grained biotite diorite granite and yellowish red porphyritic biotite granite. Through the study on inclusions, length/ width ratio, grain size, rare earth, uranium and thorium of zircon and other accessory minerals, the authors consider that the original rocks of the J rock body are sedimentary metamorphic rocks.The rich uranium, rich HREE in zircon and the hydrothermal type accessory mineral assemblage of the rock body provide basis for the evaluation of uranium potential in the studied area.