THashtag marketing utilize hashtag that focuses on specific SNS channel regardless of communication characteristics, and uses hashtag to increase connectivity with other SNS and induce user’s voluntary participation through specific SNS. On the other hand, domestic hashtag marketing suggests that there are many cases where users perceive the hashtag as advertising messages led by the company rather than perceive it as two-way communication by using the hashtag as a marketing campaign form on multiple SNSs. This study is about hash tag marketing that is used as an aggressive communication strategy on SNS. The purpose of this study is to suggest the methods and implications of effective communication between companies and consumers by comparing and analyzing cases by SNS hashtag marketing type and country. To this end, this study conducted a literature study and a case study in parallel. In the literature study, previous studies related to the characteristics of SNS evolution, communication theories, and hashtag marketing were reviewed. In addition, this study compares hashtag marketing by SNS type through domestic and international case analysis and draws implications for companies to execute hashtag marketing.BR The results of this study suggest that the hashtag strategy for SNS type and the culture of the country is required for the spread of hashtag marketing at the present as the function of hashtag evolves from barcamp to chasm on SNS.