Abstract: This paper analyzes phase and potential characteristic of Dongpu depression based on the phase-potential reservoir control theory and finds out coupling dependence between phase and potential.It is thought that reservoir formation of Dongpu depression accords with phase-potential reservoir control law.Qianliyuan sub-depression and Liutun-Hai-tongji sub-depression within the pressure compartment point to the reservoir exploration direction.Abnormal high pressure developed in the compartmetn provides enough power for hydrocarbon migration.The condition for poten-tial is preferable.Different types sandbodies were developed in the sub-depression.Abnormal high porosity was also de-veloped in the sandstone,forming good carriers for lithologic reservoirs.The condition for phase is suitable and hydrocar-bon source rock in the sub-depression is also of good quali-ty being in the period of oil generation peak,which is easy to form various types of self-generation and self-preserving lithologic reservoirs.