Abstract: Jurassic system is of wide distribution in the Northwestern of China.It is important for not only exploration and development of petroleum and coal but also the research of regional structure evolution history, to recognize correctly the deformation characteristics of the Jurassic. The author finds out the imbricate thrust structure within low Jurassic series in Qidam basin Lenghu 5 fold core and considers the structure formed in late Yanshan movement. This finding is important for understanding the nature of Yanshan movement and evaluating correctly petroleum and coal resources in the region. The structure growth history of Lenghu 5 in Mesozoic and Cenozoic eras can be divided into five stages which are early Jurassic epoch extension rift stage, late Yanshan imbricate thrust stage, early period of Paleogene contemporaneous reverse faults growth stage,from late period of Paleogene to middle period of Neogene anticline growth stage and from late period of Neogene to Quaternary the anticline reformed stage.