This presentation covers the constitution of social community in real-world, which relatively connects to the development of online social networking software. "Friendster", the one of social networking software, would be the main topic in terms of analyzing the online social community in this case study. The issues of consideration on the virtual community relatively affect the degree of trust on Friendster. However, the varieties of countermeasures toward the issues have been taking into the system for constructing an appropriate social community on virtual network.