Social Networking is a buzzword in modern communication for eradicating the distance barrier. Due to the advancement in Information and Communication Technology, peoples can communicate with each other from anywhere in anytime. Different way of communication tools exits; Social networking is one of them. Through social networking, users can share their thinking, values, emotions, insights and so on with others. However, their behaviour of the social networking sites (SNS) users is influenced by different factors. This paper aims at identifying those determinants, specially the sociotechnical determinants of knowledge sharing behaviour among the user of SNS. Structural equation modelling (SEM) was conducted on the primary data collected through the survey. Therefore, the outcome of this study shows that ethical culture, social ties, sense of belonging, knowledge selfefficacy, information privacy and structural assurance are all significant variables as socio-technical factors. This study provides a guideline to the different group of people likemarketers, employers who need to understand the knowledge sharing behaviour of the SNS users.