The sulfur content of crude oil in the eastern section of the southern slope belt（south slope）of Dongying Sag is regularly distributed：The sulfur content of crude oil gradually decreases from the center of the subsag to the edge in the planar direction，whereas high-sulfur crude oil is mainly developed in the middle-shallow formations in the vertical direction.Typical continental high-sulfur crude oil is developed in the study area，with high density and high viscosity on the whole，high proportions of non-hydrocarbons and asphaltenes in group components，and heavier carbon isotopes in group components. The geochemical characteristics of crude oil reveal that high-sulfur crude oil originates from source rocks developed under sedimentary water bodies with high salinity and great reducibility. Differences in biomarkers of high-sulfur crude oil in different regions reflect different main genesis of the crude oil. The high-sulfur crude oil represented by that in Le’an Oilfield has small burial depth，high maturity，high water body salinity，and high degree of biodegradation，while the high·sulfur crude oil represented by that in Wangjiagang Oilfield is characterized by large burial depth，low maturity，higher water body salinity，and low degree of biodegradation. The main genesis of the former type of high-sulfur crude oil is that the relative enrichment of sulfur during biodegradation and refilling after crude oil degradation lead to reduced sulfur content.In contrast，the latter type is the result of hydrocarbon generation at an early stage from high-sulfur hydrocarbon-generating parent materials deposited in a reducing water body. Thermochemical sulfate reduction（TSR）reaction may have played a role locally. Thus，in a continental basin，the high-sulfur hydrocarbon-generating parent materials formed in a highly reducing environment are the basis for the formation of high-sulfur crude oil，and secondary actions such as biodegradation and TSR are important factors for the further increase in the sulfur content of crude oil.