Abstract：Qaidam Basin is a large superimposed basin modified strongly in late history.Restored Prototype Basin is the key factor of finding source rock and oil and gas breakthrough.It is particularly important that recognizing the syndepositional uplift for the research of basin prototype.This study confirmed the developing characters and distribution of Ounan uplift during early Middle Jurassic by using abundant information of outcrop, drilling, seismic and delicate correlation.The results indicate that the palaeohigh contain current Ounan sag and Xitieshan-Aimunike Mountain.Ounan uplift is a whole during early Middle Jurassic, which control the distribution of a depositional system and the development of source rock.While in the late stage of the Yanshanian, it divided into two parts.According to the characteristics of evolvement and the remnant strata, it suggests that the north of the palaeohigh present higher exploration potential.Source nearby exploration is the primary targets based on the researching of petroleum preservation conditions and transportation system.

Keyword：basin prototype;superposition;Jurassic;sedimentic absence;source nearby exploration;