Information and communications technology (ICT) not only improves public service delivery but also enables governments to better engage citizens, called "e-participation." Although efforts have been taken to promote citizen participation online, e-participation utilization remains at a low level. To better understand this phenomenon, scholars have explored the factors affecting citizens’ e-participation usage, such as sociodemographic characteristics, Internet usage, political perceptions, off-line political activities, and so forth. However, the role of e-participation applications’ functionality has been overlooked. Using data from the 2012 European Union (EU) eGovernment survey, this study found that functionality is positively associated with citizens’ e-participation usage and high-level functionality motivates citizens to use e-participation more.