In the era of information explosion, desire for high-quality information has triggered the development of paying-for-knowledge. Even paying-for-knowledge has interesting business model, there are several problems to be solved, and one of the most salient problem is what influences users’ payment behaviors. Previous researches indicate that trust is one of the most important factors in paying-for-knowledge. However, the specific influence mechanism of trust remains unknown. In this paper, we tried to estimate the effects of character trust and situational trust. For validating our hypotheses, text analysis and economics are combined in this research. The authors find that competence-based trust, benevolence-based trust and situational trust all have positive effects on consumers' behavior of paying-for-knowledge. The findings are expected to help the sustainable development of paying-for-knowledge.