Abstract: In recent years, distribution asset efficiency has become important in power system planning. However, there are a great many factors that influence the power distribution network asset efficiency. It is essential to develop a method to find the key factors and take measures to improve the asset efficiency. This paper proposes constrained utilization maximum estimation (CUME) model to reflect the distribution asset efficiency. Gray relation analysis (GRA) has been used to calculate the relevancy to the related factors. A case study has been given as an example to indicate that the proposed method could reflect the potential relationship between asset efficiency and operating index.