Abstract：Based on seismic sections and logging data, the paper uses high-resolution genetic stratigraphy theory taking datum as reference plane, presented by Mr. Cross, and datum cyclic upturn and downturn approach to identify 3 secondary sequence-stratigraphic interfaces and 5 third-order sequence- stratigraphic interfaces inside the Tertiary of the sag, build up Tertiary high-resolution isochronal sequence-stratigraphic framework in east sag of Liaohe basin and divide the Tertiary into 2 long-term and 7 middle-term datum cycles. On that basis, the paper studies fill-up pattern of sedimentary formation and distribution of sedimentary system at different tectonic evolutional stages, analyzes main controlling factors of formation framework and predicts the development and distribution of favorable reservoirs within separate sequence-strati-graphic framework. The paper points out that there was the palaeodrainage pattern developed on both sides of sag,favorable area to develop fan delta or turbidite fan,and pointed out the direction for looking for subtle oil/gas reservoirs.
