The high penetration rate of mobile internet access makes the social networking tools ubiquitous. Through social networking tools, people now can easily contact others for social purpose as well as for work purpose. As a result, mobile social networking tools are now blurring the boundary between work and family domains and creating a new work-life relationship. Using social networking tools for work provides a lot of benefits as well as some negative effects. In the paper, we develop two empirical studies to examine both the positive effects and negative effects of using social networking tools for work. Our finding indicates that using social networking tools increases group effectiveness, which results in improvement of group identity. Nevertheless, using social networking tools for work also blurs the boundary of work-life, which may raise the work load and work-home conflict. We concluded that both academics and practice should pay attention to and minimize the negative impact of increased work overload and work-home conflict induced by using social networking tools for work. Our research results also provide suggestion for future research.