Abstract: There occur Sinian strata in the vicinity of Xichong,Qidong county , Hunan province.Through sorting strati-graphic units,it is found that a sequence of strattq dominated by slate （ with some iron-formations in the lowerpart）exposed above the Chang ’ an Formation and below the Datagpo Formation has some similarities to the FuluFormation but is nobably different from the latter in respect to the ratios of the lithologic associations. Therefore,a new formation named the Xichong Formation is establishd for this sequence of strata,whose age is Early Sinian.