Researchers found that economics has a negative effect on students’ trust and cooperation. It is proposed and found that homo economicus belief, the most basic humanity hypothesis of economics, inhibits trust. However, individual’s real trust level was affected by trust domains. It is reasonable to hypothesize that the effect of homo economicus belief on trust was moderated by trust domains. This study proposed that the categories (social vs. economic) that trust domains belonged and the risk extent of trust domains are two possible factors may influence the proposed moderating effect. According to the two factors, this study investigated the moderating effect of trust domains on the influence of homo economicus belief on trust. Four domains were selected, that is, trust in borrowing (high risk, economic interactions), consumption (low risk, economic interactions), donation (high risk, social interactions), and election (low risk, social interactions). A prior study supported our analysis of the four trust domains. Study one investigated the effects of direct learning of homo economicus belief on trust in four domains. One hundred and thirty-five college students (57 females) were randomly assigned to one of two conditions: experimental or control condition. Before testing participants’ trust in four domains, participants in experimental condition had to transcribe an introduction of homo economicus belief while those in control condition had to transcribe a passage about psychological methods (the activation effect was supported by a prior study). After then, participants’ trust in four domains was tested. Repeated measurement ANOVA showed a significant interaction effect between study conditions and trust domains, F(3, 393) = 2.66，p < .05, ?2 = .02, which supported the moderating effect of trust domains on the influence of homo economicus belief on trust. In consumption domain, trust of participants in experimental condition was significantly lower than that of participants in control condition. That is, homo economicus belief inhibits trust in consumption domain only. Study two investigated the effect of indirect activation of homo economicus belief on trust in four domains. One hundred and thirty-eight college students (85 females) were randomly assigned to one of two conditions: experimental or control condition. To activate the homo economicus belief of participants in experimental condition, they were required to unscramble 10 five-word sentences, dropping an extraneous word from each to create a grammatical four-word sentence. Five of 10 sentences in experimental condition contained words that related to economy: profit, market, trade, economy, and consumption. Ten sentences in control condition were consisted in economy-free words. After then, participants’ identification with homo economicus belief and trust in four domains were evaluated. Results showed that participants in experimental condition were higher identified with homo economicus belief than participants in control condition (t(136) = 2.43, p < .05, Cohen’ d = .41), the homo economicus belief of participants in experimental condition was activated. Repeated measurement ANOVA showed a significant interaction effect between study conditions and trust domains, F(3, 408) = 4.51, p < .05, ?2 = .03. Post hoc tests revealed that homo economicus belief inhibits trust in consumption domain, which supported the moderating effect of trust domains on the influence of homo economicus belief on trust too. In sum, trust domains moderate the influence of homo economicus belief on trust. That is, homo economicus belief inhibits trust in low risk economic domains such as consumption.