East Tianshan is an important concentration area of Cu-Ni-sulfide deposits in Xinjiang. New advance has been obtained in this area, such as the discovery of the Tianyu, Baishiquan and Tulaergen deposits. New Re-Os age data are reported in this paper, i.e. 835 Ma, 410 Ma and 286 Ma for the rock-forming and ore-forming ages of the Tianyu, Pobei and Baishiquan deposits respectively. This result suggests that the Mafic-ultra Mafic Mag Matism-related Cu-Ni-sulfide deposits in the East Tianshan area not only formed during the Hercynian stage, but also during the Caledonian and Proterozoic stage, opening a new window for further prospecting for Cu-Ni deposits.