Knowledge is a fundamental asset for firms in the contemporary economy. Promoting knowledge sharing within organizations is an increasingly important challenge for managers. Past literature in organizational studies has focused on personal motivations to explain knowledge sharing behaviors. We see an organization as consisting of multiple networks simultaneously, e.g. informational, structural, and relational networks. We propose a model to understand the individual knowledge sharing behavior from informational, structural, and relational perspectives in an organizational context. We find that in the context of interpersonal task related knowledge sharing, perceived value of knowledge, empathy and dependence play a critical role in knowledge sharing while the impacts of competition and relationship building are insignificant.