Abstract：The Cangshuipu Group is developed between the Lengjiaxi Group and Banxi Group in Yiyang area of Hunan Province, located in the middle part of the Jiangnan orogenic belt. It is considered that the study of its position in chronostratigraphic column can solve the problem of the initiation of the Jiangnan orogenic belt. The authors obtained a SHRIMP zircon U-Pb age of 821±13 Ma from the volcanic rocks in the Cangshuipu Group. This age suggests that the volcanic rocks represent a volcanic event before the Wuling movement (820 Ma), which was related to the initiation of the Wuling movement, with the volcanic tuff of this volcanic event being the product of the same tectonic movement as the volcanic tuff in the Lengjiaxi Group.