The Hetianhe gas field is one of the typical anticline gas reservoirs found in Mazatage structural belt of southern Bachu uplift in Tarim Basin.Previous exploration drilling is focused on core of the structure and the depths of exploratory wells are relatively shallow.Moreover

the quality of seismic data acquired on the flanks is poor.Therefore

structural interpretation was high in uncertainty.This paper tried to reinterpret the 2D seismic data based on calibration with drilling data and application of faulting-related fold theory.The result shows that the Mazatage structure is dominated by detachment anticline with the Middle Cambrian gypsum as detachment surface

while the part in the east of well Ma-4 in the structure is a fault-propagation fold

indicating the existence of a near NS-trending transverse strike-slip fault(seismic profile also revealed the same conclusion).Seismic interpretation also indicates that a thrust fault named Gudongshan deve-loped on the northwest flank of the structure extends into the Hetianhe gas field.The Miocene-Pliocene growth strata and Quaternary angular unconformity developed on the south and north flanks in the detached anticline show that the structure was probably formed during the Miocene-Pliocene period and reactivated during the Quaternary.