Research conclusions :(1) The theoretical analysis and practical calculation results show that the safety coefficient or partial coefficient of retaining structure and reliability index are positive correlation. (2) The reliability index is closely related to the retaining structure limit state, corresponding to different status and safety forecast, the reliability index of the different classification should be adopted. (3) Based on viewpoint of system engineering, the reliability of retaining structure is maintained in the same level, each partial coefficient calculated in retaining structure design should be adjusted according to the analytical result of reliability index. (4) Reliability index classification of retaining structure in this paper and the viewpoint of partial coefficient adjustment based on same reliability requirement can be directly used to guide the design of the retaining structure.