中文摘要：

随着网络技术的快速发展，社交网站为广大用户提供了一种全新的交流和信息分享的平台，深受网友的欢迎。本文探讨了社交网站的交互模式，以测试来自传统物理世界的成本、互惠性、三方闭合、同质性等理论应用在虚拟世界是否有效为重点。尽管结果显示社交网站交互结构和属性变化与现实世界中的社会网络的结构有所不同，但他们在一定程度上影响了社交网站中用户交互的形成。毫无疑问，这些发现对于需要理解社交网站发展过程的研究者和实践者有重要的启示作用。

英文摘要：

With the rapid development of the Internet technology, social networking site get more and more popular as they provide customers a novel communication and information-sharing platform. This paper examines how users interact in social networking sites and futher explore whether the traditional theories on cost, reciprocal, triad closure and homogeneity in the physical world would be still valid in the virtual world. Although the results show that the structural effects and demographic variables in social networking site are different from ones in the real world, they are to a certain extent affect the formation of user networks and their interactions in online social networks. These findings have important implications for researcher and practitioners who need to understand social processes well to develop and sustain healthy and satisfactory social network site.