Analysis and test data of reservoir water of Huzhuangji-Qingzuji oilfield in western Dongpu depression shows that the water type is CaCl2 and is of high salinity. The chemical composition mainly includes C1- and Na+ and controlled the spatial distribution of the reservoir water’s composition. This is caused by saline lake sediment environment. Due to the water-rock interaction, the ions, such as Ca2+, Mg2+, CO32-, SO42-, have less correlation with salinity. Two underground hydrodynamic cycles have developed corresponding to Paleogene and Neogene- Quaternary respectively. The first cycle could be divided into two stages: ①clay compacting water centrifugal flow stage during Shahejie-Dongying subsidence; and ②atmospheric water filtration centripetal flow stage during Dongying uplift. The clay compacting water centrifugal hydrodynamic is positive to hydrocarbon accumulation, moreover, and the atmospheric water filtration centripetal hydrodynamic re-build reservoirs formed in western slope of Dongpu depression. The favorite belt for oil accumulation is from the intersection area of the two different hydrodynamic stages to the second terrace of the depression. The first terrace is formed in Neogene-Quaternary, which is of stagnant hydrodynamic conditions, and the self-generating and self-preserving reservoirs could develop there.