Team productivity is one of the issues that always been considered in the software development teams. In software development process, as a team-oriented process, team productivity is a serious issue in software competitive industry that always gets high attention. Several studies have been conducted on various aspects of team productivity, but because of role of employed methodologies, providing a unified model in this regard is not possible. This article is specifically aimed to focus on team productivity in XP methodology and provide a productivity model dedicated for this method. The proposed model is developed based on the most influential features affecting team productivity. This model evaluated and gained enough acceptance. The article also shows the most effective XP practices that positively impact team productivity in XP projects.