This paper carries out a study of the age distribution of detrital zircons of sandstone in Shaleisaierke formation and Shamaershayi formation, which supposed to be Carboniferous system, in approach of LA-ICPMS U-Pb isotopic age of zircons. It is indicated that the sample of Shaleisaierke formation has a wide range of zircon age distribution from 298Ma to 2215Ma, but mainly distributed between 298Ma and 344Ma, it has a dominant peak at 305Ma, and a lesser peak at between 501～538Ma. In addition, there is also one detrital zircon with age of 1354Ma, and another two detrital zircons with ages of 2146 Ma. and 2215Ma；But the Shamaershayi formation has a narrow(280Ma～523Ma)and centralized age distribution(299～358Ma), with a dominant peak at 345Ma, and some lesser peaks between 428～450Ma and 507～523Ma, respectively. According to the petrology of sample, the content of Th &U，CL image of dated zircon, in combination with regional geology analysis, the authors come to the following conclusion: (1)the age of the stratum in the north part of Bogda mountain, which supposed to be Carboniferous system, is from early carboniferous to early Permian. The age of Qisiguertao Group、Julideneng formation～Yangbulake formation and Shamaershayi formation should be later early Carboniferous to early later Carboniferous、middle to later later Carboniferous and early Permian accordingly, but the age of Mulintuokaitaoshan formation and its relation to the Shamaershayi formation should carry out further study；(2)the provenance of the sandstones in Shaleisaierke formation and Shamaershayi formation come from the eastern of Junggar basin, and the main source of the sandstone is the Carboniferous stratum in the study area, which formed earlier of during the age of the stratum formed；(3)the Bogda rift started from early carboniferous, and begin to decay in late carboniferous with twice weak orogeny events, then finally declined in Xiazihe stage of middle Permian.