The mafic-ultramafic complex in the Xiangshan area of the eastern Tianshan Mts., Xinjiang, produces the medium-sized mid-Xiangshan Cu-Ni deposit and the large-scale western-Xiangshan Cu-Ni-(V)-Ti-Fe deposit. These complex rocks are composed of gabbro, ultramafic rocks and Ti-Fe gabbro. Field evidence indicates that these complex rocks intrude successively. This paper aims to prove their intruded order through combing age data of various rock series, and complementing the dating data. We suggest that the complex rocks intrude at 283.2±2.1Ma, and report some data recording tectonic-magmatic thermal event. Using the results of hornblende 40Ar/39Ar age data, we insist that the western-Xiangshan rocks are hypogene, but the mid-
Xiangshan rocks are hypabyssal, with the results of U-Pb zircon data. Thus, we believe that the erosion amount of the western-Xiangshan rocks is big, but that of the middle-Xiangshan rocks is small. Combing the field evidence, we determined the emplacement and mineralization timing orders of complex rocks in Xiangshan area.