Abstract: Manghan fault depression is situated in southwestern uplifted area of Songliao basin, being reconstruction basin. Without sufficient understanding of its tectonic evolution, the analysis about its petroleum geological condition can not meet the requirements of petroleum exploration. With balanced section method, study of tectonic evolution of Manghan fault depression has been conducted, and the tectonic character in different period has been understood. In addition, the tectonic framework has been made clear in the study area, and the influence of the tectonic evolution on hydrocarbon source rock, reservoir, trapping and the major control factors for HC accumulation have been pointed out.