Abstract: Zircon ages (825Ma±5 Ma) and (830Ma±6 Ma) of tuff in the Chentangwu Formation are reported for the first time from the "Pingshui Group" in Pujiang County, Zhejiang Province. In combination with the SHRIMP U-Pb age (824Ma±5 Ma) of the tuff from the Xiushui Formation and 825Ma±5 Ma of the rhyolite from Xingzi complex Group and the SHRIMP U-Pb age 840Ma±6 Ma of the spilite, the U-Pb ages of the rhyolite(833Ma±4Ma and 831Ma±3Ma) in the Shaoqiwa Formation of the Lushan Mountain in the north part of the Jiang-Shao fault zone, the Chentangwu Formation should be located below the Wuling Movement at 820 Ma and just above the Zhangcun Formation of the Shuangxiwu Group, not belonging to the traditional Pingshui Group. The authors consider that the Mengshan Formation, which is below the Chentangwu Formation, is correlated with the lava pillow and spilite of the Shaoqiwa Formation in Lushan area. The reconfirmed age of the Chentangwu Formation is of important significance for the stratigraphic correlation and tectonic evolution study in the Jiang-Shao fault zone.