Abstract: Based on cores，log and welllog data, under the guidance of the theory of the highresolution sequence stratigraphy, evolution of all levels baselevel cycles and highresolution sequence stratigraphic model were analyzed in the A region of Lucaogou Formation of Jimsar Sag. The results show that 1 longterm, 6 middleterm and 44 shortterm baselevel cycles were classified. According to the structural feature, stacking pattern and spatial variation of shortterm baselevel cycle, the authors established A region of Lucaogou Formation highresolution sequence stratigraphic framework. By analyzing the sequence structure, stack style and space variation, suggested that sedimentary facies types and controlling factors of the high quality of tight oil reservoir is obtained by shortterm baselevel cycles; Concluded that the high quality of tight oil reservoir is located at the conversion surface of 2 eustatic cycles and formed a depositional system of carbonate and siltstone sheet from shallow to semideep lake, therefore, the 2 cycles of falling semicycle control the tight reservoir development and the types of microfacies control the position and quality of dense reservoir. This has important significant to guide the high precision stratigraphic subdivision in A region and even the salt lake facies.

Key words: highresolution sequence stratigraphy, baselevel cycle, stratigraphic framework, salt lake, Lucaogou Formation, tight oil