Hong Kong, a quasi-democratic society, provides a unique context for the study of political participation. This study documented Hong Kong’s political sentiments during a critical transitional period in its democratization process. A random-sample telephone survey examined Hong Kong residents’ sense of political efficacy, their propensity to participate in protest activities under British and Chinese rule, and their response to the possible enactment of a national security bill before the controversial legislative process precipitated an unprecedented political crisis in 2003. Results showed that people with a higher degree of internal political efficacy and a lower degree of external political efficacy were more likely to engage in protest activities. Such findings provide a reference point for future studies on Hong Kong’s public opinion toward protest activities.