The carbonatite- type Mo- U polymetallic deposits in the eastern Qinling mainly comprises of the Huayangchuan U polymetallic, the Huanglongpu Mo, and the Huangshuian Mo deposits. The Huayangchuan is a super- large U- Nb- Pb deposit accompanying rare- earth elements, and the Huanglongpu is a unique large scale Mo deposit in the eastern Qinling molybdenum belt. In this paper, we use molybdenite Re- Os dating and LA- ICP- MS monazite U- Pb dating to precisely determine the timing of the carbonate- type Mo- U polymetallic mineralization in the eastern Qinling. The Re- Os dating of molybdenite samples from the Dashigou Mo deposit yields a Re- Os isochron age of 221. 3±8. 4 Ma. The LA- ICP- MS monazite U- Pb dating in carbonate dyke from the the Qinlinggou Mo deposit and the Huayangchuan U polymetallic deposit yielded Tera- Wasserburg concordant ages of 207±11 Ma (MSWD=3. 7, n =38) and 222. 5±6. 7 Ma (MSWD=1. 8, n =37), respectively. These ages show that U polymetallic and Mo mineralization in carbonates occurred in the Late Triassic. In conclusion, the Huanglongpu Mo orefield and Huayangchuan U polymetallic deposit, which occurred in carbonatites, were formed in the same mineralization series. The ore- forming materials of carbonatite- type Mo- U polymetallic deposit may derived from the mantle, and the carbonatites may be the products of the post- orogenic extensional setting in the Qinling Orogenic Belt.