The Shixi area is located in middle of eastern margin of Ordos Basin, where tight sandstone gas resources are abundant. It is important in theory and practice to find out the development of source rocks and their controlling for oil and gas exploration. Methods: In this paper, the source rock samples of the Benxi Formation, Taiyuan Formation and Shanxi Formation from the Well SX- 16 in Shixi area were collected, and their organic and elemental geochemistry characteristics were determined by Leco CS- 200, Rock- Eval 6, ICP- OES and ICP- MS.Results: It may be concluded that the average values of total organic carbon content, hydrocarbon generation potential (S1+S2) and hydrogen index (HI) of carbonaceous mudstone are 4.50%, 0.52‰ and 829.16‰, respectively. The average values of total organic carbon content(TOC), hydrocarbon generation potential (S1+S2) and hydrogen index (HI) of coal are 61.53%, 4.41‰ and 723‰. The ratios of V/(V+Ni), Ni/Co, V/Cr, δU, Sr/Ba and Sr/Cu indicate that the high quality source rocks were deposited in a warm and humid environment with high salinity and oxidation—reduction environment. During the deposition process from the Benxi Formation to Shanxi Formation, the reducibility of sedimentary water tends to decrease gradually. The paleo- productivity index (NiEF and CuEF) shows that the paleo- productivity of the Shanxi Formation is the highest, followed by the Taiyuan Formation and the Benxi Formation.Conclusions: The main controlling factors of organic matter enrichment in source rocks in the study area are paleoredox environment and paleosalinity, and paleoclimate and paleoproductivity level play an important role in the enrichment of organic matter in source rocks.