In recent years, social media has entered enterprises as a tool for internal communication, collaboration, and knowledge management. However, it has been reported that knowledge contribution rates are low which raises questions on the reasons for it and how to improve the situation. To address these questions, we take a deep look into the individual knowledge contribution process using an integrative model that explains the initial formation of the intention to contribute knowledge and the continued knowledge contribution. Towards this goal, we apply the theory of reasoned action, the social exchange theory, and the belief-adjustment model. In this research in progress, we present our research model and a test covering the first part of the model, the formation of the intention to contribute knowledge. The results suggest that social exchange theory and theory of reasoned action are well suited to explain this phenomenon and that they build a good basis for the second part of the longitudinal study.