Social media have been growing rapidly in recent years thanks to the innovations of social networking sites (SNS) such as Facebook and Twitter, both of which originated in the United States. Currently, SNS and other social media have become global phenomena. This report aims to study the features of SNS that prosper in the U.S., Japan, and China. Through a comparative analysis of the similarities and differences among the top SNS players in each of the three countries, it is possible to identify unique characteristics of each nation’s social networking landscape. The SNS market in the U.S. is relatively mature, while the social networking population is growing in Japan and China. However, contrary to the expectations of some, the Japanese and Chinese social networking landscapes appear to be quite different from one another with regard to SNS usage, despite Japan and China’s similar cultural backgrounds and geographical proximity. / text