In order to determine the formation time and provenance of the Xinxing Formation of Zhangguangcailing Group, this study carried out geochronological analyses on detrital zircons and magmatic zircons from the study area. Several groups of the concordant ages for two groups of detrital zircons from the Xinxing Formation were obtained in this study using LA- ICP- MS U- Pb dating method. The minimum peak (concordant) age for 91 points of sample BP18R15 is 260 Ma (41 points), while the minimum peak (concordant) age for 100 points of sample BP18R83 is 253 Ma (52 points). The minimum single point age was 192 Ma and 207 Ma. CL images show that most zircons are euhedral- subhedral in shape and present finescale oscillatory zoning, as well as high Th/U ratios, implying their magmatic origin. The study above suggests that the lower limit of the Xinxing Formation should be the late Permian. Combined with the age (210±1 Ma) of syenogranite intruding into the Xinxing Formation, this study believes that the Xinxing Formation of the Zhangguangcailing Group formed between late Permian and late Triassic, rather than the Neoproterozoic as previously believed. It can be concluded from the age frequency of detrital zircons from the Xinxing Formation that the sediments of the Xinxing Formation came mainly from the late Paleozoic geological bodies in surrounding areas, with minor from other geological bodies with time range from Mesoproterozoic, Neoproterozoic, and Early Paleozoic to Early Mesozoic. Existence of Precambrian detrital zircons implies that the Precambrian residual geological bodies might occur in regional surface or shallow crust during the deposition of the Xinxing Formation. Almost all of the sediments in the Xinxing Formation sourced from the SongnenZhangguangcailing massif, suggesting that the collage of Songnen- Zhangguangcai massif and Jiamusi- Xingkai massif and north China massif should occur later than the late Permian.