In Northwest of Lesser Hinggan Mountains, some deformated granitoidse outcrop with Proterozoic metamorphic rocks. The writers studied these granitoids on petrology, geochronology and petrogeochemistry. Five samples are granodioritic mylonite（sample I 3 4, I 5 1), brecciated granodiorite(sample 1121,1211) and granitic mylonite (sample 1218) respectively, and the corresponding primary rock formed at 299.6±1.0Ma, 300.8±1.1Ma and 294.3±1.0 Ma of the Late Carboniferous and the Early Permian, not the Proterozoic or Early Carboniferous that the predecessors determined. It is deduced that the ductile deformation happened at 184~170Ma. Petrochemically, these rock belong to Peraluminous calc alkaline serie with high Si, Al, low K(sample I 3 4, I 5 1), and Metaluminous high K calc alkaline series with high Ca, Fe, Mg, low Si(sample 1121,1211), and Peraluminous shoshonite series with high Si, K, low Ca, Mg, Al(sample 1218). They enriched in LREE, depleted in HREE relatively, and have negative Eu anomalies. They enriched in Rb, La, Th, U, and depleted in Sr, Nb, Ta, Zr. All these characters show that these granite are high fractionated I type granitoids and A type granite. The discriminant diagram of tectonic environment show they formed in syn collision, late orogenic and post orogenic environment respectively. Combined with regional geological data, writers propose that these granite are formed during the collision and orogen of the Hinggan(Xing’an) block with Songnen(Songhua River—Nenjiang River) block in Late Paleozoic.