Abstract: Open government data (OGD) has become a key policy initiative for developing modern governance capacity and responding to big data development strategies. The formation of collaborative networks among policy actors is a driving force to eliminate data gaps and enhance the value of data. Using social network analysis, this study explores the evolutionary characteristics of collaborative networks of OGD policy actors at the national level. The results show that the scale of the network has continued to expand and that its density has increased over time. The overall network has experienced structural evolution from a "core, periphery" to "core, semi-periphery, periphery" configuration, indicating a trend toward multi-centered coordination and balanced development. The network actors have shown an increase in the breadth and strength. Core actors such as the National Development and Reform Commission exhibit increasingly stable and central positions. However, several problems remain including limited network stability, low information transmission efficiency, and mismatches between authority and responsibility. These findings highlight the need to clarify the interests and responsibilities of policy actors and to leverage the coordination capacity of core actors.