As an important part of railway freight transport, the healthy development of container transport is of great significance for promoting the adjustment of China's transportation structure and support the new pattern of transportation development.Based on the data of railway container loading and unloading station, this paper uses social network analysis and community discovery algorithm to explore the evolution characteristics of transportation network after the reform of railway freight marketization.The results show that:1) The number and volume of handling stations have obviously increased, and the later growth shows the characteristics of lag and balance. Railway container transportation is providing strong support for ensuring the stable operation of the national economy. 2) The transportation backbone network is composed of Kunming, Fangchenggang, Changji, Shihezi, Yingkou and other cities, and the "regional-gateway" structure is obvious throughout the country.From the functional point of view, Chongqing, Chengdu and Kunming play a significant role as "bridges", while cities such as Urumqi and Changji have obvious transit functions.3) The spatial proximity and spatial jumping characteristics of group characteristics coexist, but the trend of fragmentation and decentralization is obvious.