LA ICP MS U Pb dating was carried out on detrital zircons from the argillaceous rocks in upper Dajiangbian Formation of Nanhuan System and the metamorphic mud ferruginous sandstone in bottom Aiqiling Formation of Sinian (Ediacaran) System, 28 and 92 effective U Pb ages were obtained respectively. The former detrital zircon U Pb age populations were at 693~897Ma（account for 67.9%）, 1810~1916Ma（account for 17.9%）, 1974~2177Ma（account for 14.2%）, the youngest concordant age was 734±4Ma（MSWD=1.07, n=4）; The latter detrital zircon U Pb age populations were at 570~699Ma（account for 9.8%）, 715~774Ma（account for 7.6%）, 882~1272Ma（account for 67.4%）, 1300~1681Ma（account for 7.6%）, 1899~2490Ma（account for 7.6%）, the youngest concordant age was 634±7Ma（MSWD=1.09, n=4）. It was confirmed that the age of the upper Dajiangbian Formation was < 734±4Ma, which can be correlated with the top part of Chengjiang Formation, Niuguping Formaion, Yanmenzhai Formation, Gongdong Formation and Longli Formation, indicated the top boundary age of “Banxi Period” strata and the start age of Jiangkou iceage should be < 734±4Ma. The age of the Aiqiling Formation was < 634±7Ma, as same as the age of the Doushantuo Formation and Lantian Formation, supported the viewpoint that the end age of Nantuo iceage was at ca.635Ma. Comprehensive research shows that the main provenance of Dajiangbian Formation and Aiqiling Formaion maybe the southeastern part of the Wuyi terrane and the Grenvillian orogenic belt in south of the Nanling Yunkai terrane respectively. The transition of provenance was speculated to be related to the coalescence or juxtaposition of the Nanling—Yunkai terrane and Wuyi terrane during the deposited period of above two formations，which maybe 734~634Ma.