Total Organic Carbon,isotope of organic carbon,phosphorus and sulfur were measured from the Upper Ordovician to Lower Silurian stratigraphic columns located in Wangjiawan,Yichang,and Sanjiaguan,Zhangjiajie.Production,accumulation and preservation of organic matter were studied with regional tectonic background in mind.It was indicated that photosynthesis played important role in production of organic matter.The produced organic matter was accumulated in marginal depression of the Yangtze Craton.The regional anoxic environment of northern Gondwana,to which the Yangtze Craton once belonged,favored preservation of organic matter.Hydrocarbon source rocks have a good exploration perspective,like that of "hot shale" deposited in North Africa.