The study of trust of consumer on Business-to-Consumer (B2C) E-commerce is one of the key research interests of Information Systems (IS) researchers. In this research, we investigate the impact of trust on two different E-payment gateways, viz. online credit card payment system and the hypothetical online Octopus card (a stored-value smart card) payment system. Based on the model developed by Gefen et al. (2003) and McKnight et al. (2002a), we synthesize our own research model by incorporating disposition to trust, and trust and its antecedents with the Technology Acceptance Model (TAM). An online survey was conducted on the Government-to-Citizen (G2C) E-commerce portal of the Hong Kong Government and 2,481 usable responses were collected. The empirical result shows that consumers in Hong Kong are using different trust building processes to consider their adoption for E-payment gateways.