Based on the analysis of TOC, trace elements of 3 typical Cambrian stratigraphic sections from platform- slope-basin in west Hunan-Hubei area. V/( V + Ni) , U/Th, Ni/Co indicated Cambrian sediment turn from strong re- ducing environment to oxidized environment, and with a few oxidation-deoxidation sediment periodicity in slope zone. After normalized by NASC, θEu with positive anomaly and θCe with negative anomaly, and the abnormal degree showed a deeperwater from platform-slope-basin, as a whole regression after transgression in Cambrian. The environ ment of source rock in the bottom of Niutitang Formation was productive, strong reducing, and transgressive ; the high TOC shale probably has relationship with reductive, nutritive elements-rich hydrothermal fluid flow, which upwelled along deep fracture during the transition from Sinian to Cambrian, and also with episodicity upwelling.