The NM deposit is located in the northwest trending magmatic-tectonic belt, north-central part of Truong Son, which was subjected to right-lateral shearing due to the collision of Sibumasu micro-continent with Indo-China micro-continent along Nan-Uttaradit suture during Permian-Triassic Period. Based on the grain size and spatial distribution, the granites in NM deposit can be classified into medium-coarse grained granite, porphyritic granite and fine grained granite respectively. The geochemical characteristics of different types of granite show that they are high-potassium, calc-alkaline granitoids with the ACNK ratios mostly ranging from 0.9 to 1.1. All of the geochemical features indicate that these different types of granites in NM deposit were derived from the same origin related to the special tectonic setting of post-collision volcanic arc.