In recent years, open government data has become an important movement among government administrations around the world. While there is still limited open data research conducted in East Asia, this study explores the complexity of open data initiatives in Taiwan. In particular, the influential factors and their impacts on open data initiatives are investigated from four perspectives: technology, organization, legislation and policy, and environment. Legislation and policy is found to have the most significant impact while agencies’ existing regulations and policies act as constraints. The factors residing in organizational and environmental perspectives follow as the secondary impacts. Technological factors also exist but are considered to be relatively more easily resolved with sufficient support. While the identified factors act as determinants to influence government agencies’ intentions towards open data participation, it is also found that open data is closely related to interagency information sharing, and the two activities in the long term are expected to reinforce to each other iteratively. In addition, practical implications are discussed to provide practitioners with insights. Lastly, the contributions, limitations and potential future research of the current study are listed in the Conclusion section.