It is very important to make administration systems efficient. Also objectivity is required in these areas. From this viewpoint, this study is aimed for developing a Policy Decision Support System for Destination Design by focusing on “Big-data”. Although destination development and design needs to be addressed by the regional approaches, the customer-oriented thinking is indispensable to such kind of arguments. Trough accumulating and analyzing Tourism Big-data with Twitter API algorithmic program, this study lead to a better understanding of the “crossborder customer” and the validity of using “Big-data” as a Decision Support System. A couple of research themes are written at the end of this paper.