The current study investigates the influence of social factors, such as self-interest and involvement, on trust and its determinants, in the context of public decision-making in government, through two scenario experiments. In both experiments, participants' involvement (high/low) and, subsequent interest in the high-involvement condition (agreed/opposed) were manipulated and two trust models were compared: a traditional model, which regards expectation about intention and competence as the component of trust; and an SVS model, which regards perceived salient value similarity as the primary determinant of trust. Two hypotheses were tested: 1) conflict of interest diminishes trust and value similarity; 2) expectation of the government's intention consistently predicts trust in government, regardless of self-interest. The results supported both hypotheses. Implications of value similarity in the context of public decision-making are discussed.