This study explores continual usage of the knowledge management systems (KMS) by employees in organizations, specifically referred electronic knowledge repositories. Based on IS continuance research that emphasizes usefulness and satisfaction, we propose that to understand KMS usage, scholars also need to examine social factors from an integrated theoretical approach. Meanwhile, the motivations of KMS usage by knowledge contributors and knowledge seekers could be distinct. We developed two theoretical models to explain KMS usage by employees in organizations for knowledge contribution and knowledge seeking behaviors respectively. The models try to examine how social relationships may affect the userâs attitude toward KMS usage. The influence of organizational facilitating conditions such as rewards, job requirements, and management commitment on attitude formation is also been incorporated. This survey results are expected to conform to the proposed model. Insights for research and practice are discussed.