Abstarct: The Ahwaz oilfield as one of the largest oilfield is located at the southwest of Iran in northern Dezful embayment. The Asmari Formation, Bangestan and Khami groups are main reservoirs, and Kazdumi, Pabdeh, baxse of Asmari, and Gurpi Formatios are forming source rocks of this oilfield. Shale, calcareous shale, marl and marly limestone with intercalations of limestone are forming the main composition of oil source rock formations. Trace and rare earth elements (REEs) geochemistry of source rock formations display that: sediments of source rock formations was derived from the felsic to intermediate igneous parent rocks. The organic matters have terrestrial and mixed terrestrial-marine sources, and source rocks are mainly deposited in a marine environment. From the view of redox condition, the A10 part from the baxse of Asmari F.and some part of Kazdumi F. are deposited under oxidation condition, whilst this situation for the other source rock formations is reduction. The upper continental crust (UCC)-normalized trace elements and North American shale composition (NASC)-normalized REEs patterns of source rocks show that discrepancy between A10 part of Asmari F. and some part of Kazdumi F. with the other source rocks, which affect from the parent rock types and redox condition of depositional environment. Comparison of Ni and V contents in the source rocks with those of crude oil in some boreholes from Ahwaz oilfield indicate negative correlation, so that the content of these elements decrease from the source rocks toward crude oil. In addition, there is a negative correlation between REEs and total organic carbon (TOC) in the oil source rock formations. Similarity of elements geochemical characteristics between A10 part from the baxse of Asmari F. and some samples from Kazdumi F. introduce the baxse of Asmari F. parallel to Kazdumi F. as oil source rocks in the Ahwaz field.