What affects the way that trust develops in negotiations? In two studies, we used an actor–partner interdependence model to investigate how both negotiators' trust propensity prior to the negotiation and two types of behavior during the negotiation affect negotiators' trust development. Study 1 demonstrated that both focal negotiators' (actors') and their counterparts' (partners') trust propensity were positively associated with negotiators' trust development. Study 2 showed that actors' and partners' trust propensity had an indirect effect on trust development via both actors' and partners' negotiation behaviors. Negotiators' trust propensity positively affected their use of Q&A (questions and answers about interests) and negatively affected their use of S&O (substantiation about positions and single‐issue offers). Actors and partners' negotiation behaviors in turn affected their own and their partners' trust development. Our studies propose and test a model to understand how negotiators' trust propensity and negotiation behaviors affect the development of trust in negotiation. Copyright © 2016 John Wiley & Sons, Ltd.