More and more people sell things online and trust is an important factor in online selling. This research is aimed at understanding the roles of trust in online sellers' continued use of online auction marketplaces. Given the uniqueness of online auction practice, we identify the need for differentiating sellers' trust in the intermediary and in buyers. A balanced view of cognitive and affective trust is incorporated with the Motivational Model of technology acceptance to predict sellers' use of online auction marketplaces. Empirical data collected from online auction sellers in uBid.com confirmed our model. Specifically, our findings show that, for online auction sellers, (1) trust has both cognitive and affective components; (2) trust in the intermediary (e.g., eBay.com) impacts trust in the community of buyers through the trust transference mechanism; (3) trusting attitudes antecede user acceptance and use factors including perceived usefulness and perceived enjoyment, which in turn influence sellers' intention to return;; and (4) perceived enjoyment is an important antecedent of sellers' retention. Besides theoretical contributions, this research also has practical implications.