Knowledge payment has become an emerging interactive mode. This research aims to investigate the influential factors driving knowledge demanders’ knowledge payment for online knowledge in emerging markets. By integrating flow experience theory and means-end chain theory, this paper reveals the relationships between each characteristic (product characteristics, demander characteristics, and platform characteristics), and knowledge demanders’ purchase intention. Hypotheses and theoretical model with product characteristics, demander characteristics, and platform characteristics of paid knowledge were proposed. 413 effective questionnaires were collected. A structural equation modeling was constructed and AMOS was used to illustrate the original estimate value of each path and correlations between items and factors. The results show that flow experience affects path dependence and perceived cost enjoyment, path dependence influences perceived cost performance. For product characteristics, perceived substitutability negatively influences perceived cost performance and purchase intention, and perceived cost performance affects purchase intention. For demander characteristics, perceived cost enjoyment positively affects purchase intention. For platform characteristics, perceived payment risk negatively influences purchase intention, while perceived payment convenience has no significant influence on purchase intention. The findings of the research provide some strategic enlightenment for content producers, knowledge payment platform managers.