Haduohe area is located in the middle of the Great Hinggan Mountains, the Erlian—Hegenshan—Heihe tectonic belt lies on its south side, this area is an ideal place to study the tectonic evolution of the ancient Asian Ocean, it can further reveal the collision—splicing process of Xingan block and Songnen block in the Late Paleozoic and provide new evidence of the demise of the ancient Asian Ocean. Based on the field work, through the microscope observation, the whole rock chemical analysis and LA- ICP- MS U- Pb zircon dating of the late Paleozoic intrusive rocks in Haduohe area. According to the test analysis results, the weighted average ages of Two stage intrusive rocks are respectively (352.1±1.7) Ma and (339.1±4.2) Ma, the ages belongs to the early Carboniferous. The average SiO2 content of medium coarse monzogranite is 73.11%, the average Al2O3 content is 13.47%, the average total alkali (ALK) content is 8.74%, the average Na2O/K2O is 1.13, which belongs to the metatretic substance. The average SiO2 content of medium—fine monzogranite is 71.98%, the average Al2O3 content is 13.82%, the average total alkali (ALK) content is 8.94%, the average Na2O/K2O is 1.15, which belongs to the metatretic substance, both of them are high potassium calc- alkaline series rocks. Two stage intrusive rocks are enriched in light rare earth and deficient in heavy rare earth, the distribution pattern of rare earth is right- leaning, which Enrichment of LILE (Rb、K、U) and Loss of HFSE (Nb、Zr、P、Ti), also have obvious Eu negative anomaly, which shows the characteristics of I- type granite. Combined with previous research results, the early Carboniferous intrusive rocks in Haduohe area were formed by magmatic tectonic events under island arc background, it indicates that Xingan block and Songnen block were still in the collision and merging process in the Early Carboniferous, the ancient Asian ocean is closing up and dying.