The Balkhash Metallogenic Belt in Kazakhstan, with the output of many porphyritic Cu-Mo deposits and some quartz-vein greisen W-Mo deposits, is a very famous porphyritic Cu-Mo metallogenic belt in Central Asian Metallogenic domain which is represented as a multiple core metallogenic system controlled by the boundary strike-slip fault system. In this paper 11 molybdenite samples from western Balkhash metallogenic belt are selected for Re-Os isotopic dating. The molybdenites from porphyritic Borly Cu-Mo deposit, and East Kounrad, Zhanet and Akshatau quartz-vein greisen W-Mo deposits, give average model Re-Os ages of 315.9 Ma, 298.0 Ma, 295.0 Ma and 289.3 Ma, respectively. Meanwhile, the molybdenites from East Kounrad, Zhanet and Akshatau W-Mo deposits give a Re-Os isochron age of 297.9 Ma, with MSWD of 0.97. Re-Os dating of molybdenites indicates that the Cu-Mo-W metallogenesis in western Balkhash metallogenic belt formed during Late Carboniferous to Early Permian (315.9 Ma~289.3 Ma), while porphyry Cu-Mo deposits formed at ~315.9 Ma, and quartz-vein greisen W-Mo deposits formed at ~297.9 Ma. The Re-Os model and isochron ages suggest that Late Carboniferous porphyry granitoid and pegmatite magmatism during Late Hercynian movement. Comparing to the Juggar-East Tianshan porphyry Cu metallogenic belt in northwestern China, the time of the Cu-Mo metallogenesis in Balkhash metallogenic belt, is between that of Tuwu- Yandong and Baogutu porphyry Cu deposits in East Tianshan and west Junggar. Concluded, the large-scale porphyry Cu-Mo metallogenesis in Central Metallogenic Domain centralized in Late Carboniferous due to Hercynian tectonic-magmatic activities.