Interaction in businessrelationships is a significant means of resourcedevelopment. Studies of these processes have focused on interactivedevelopment in long-term relationships between buyer and supplier. This study explores the characteristics of joint resourcedevelopment in newbusinessrelationships, where the two parties have no previous experience of interacting with each other. The study is based on the industrial network model and contains two cases of interactivedevelopment of new products with entirely different features. This research shows that joint development in a newrelationship is strongly dependent on the resources of other business partners, since no previous adaptations exist between the two focal actors. Access to these resources is achieved through the established businessrelationships of the two parties. Furthermore, previous interactions with other business partners have a significant impact on the outcome of interactivedevelopment in a newbusinessrelationship. The main reason for these conditions is that the features of the resources of the two parties have evolved during these interactions.