Along with the drastic competition among ports, the strive for the vast economic hinterland and the supply of goods have become strategic problems for port operators. At the same time, port enterprises are paying more and more attention to the construction of dry ports. This article establishes the port cooperation performance evaluation index based on the balanced score card method and uses the grey relational degree method to evaluate the cooperation performance between seaports and dry ports. Finally using Qingdao port and Xi'an port as an example, and Zhengzhou port and Lanzhou port as benchmarks, the application of this evaluation method is introduced in detail. The conclusion reveals that cooperation between Qingdao port and Xi'an port has deficiencies in customer satisfaction, financial cooperation and non-market tools. Alongside this, the author proposes related issues about information management in the supply chain, competition position and the scope of hinterland. This article, combined with the related theory of supply chain and performance evaluation, puts forward a set of relatively complete cooperation performance evaluations between seaports and dry ports, which provide scientific theory support for better cooperation.

Abstract
I. Introduction
II. Theoretical Basis
III. Research Methods
    3.1. Indicator System
    3.2. Selecting the Benchmark
    3.3. Calculation Methods
IV. Examples
    4.1. Select the Benchmark Dry Port
    4.2. Select the Benchmark Dry Port
    4.3. Weighting by Analytic Hierarchy Process
    4.4. Calculating the Grey Correlation Degree
    4.5. Determining the Grey Relational Degree of Dry Ports
    4.6. The Analysis of the Results
V. Conclusions
References

• Jian LI(College of Economics, Ocean University of China)
• Bao JIANG(College of Economics, Ocean University of China) Corresponding Author