Despite the importance of motivation in information systems (IS) research, past research has not paid much attention to the issue of what motivates people to evaluate IS success. Drawing upon DeLone and McLean IS success model, eCommerce literature, psychological involvement, and personality, this study investigates determinants of the motivation to evaluate IS success in the context of charity websites. In particular, this study proposes and tests a Motivation Development Model, which includes causal relationships among personality, psychological involvement, and motivation to evaluate IS success. This model provides a theoretical understanding of what makes people evaluate various aspects of IS success by demonstrating that prosocial personality increases psychological involvement with charitable giving, which in turn motivates the evaluation on IS success of charity websites.