Data publication is becoming an essential part of today's research activities. In some disciplines, data publication is a condition for submitting a paper, there are legal aspects such as international treaties that make it obligatory, so the construction of disciplinary repositories that promote the publication and utilization of research data is an urgent issue. In recent years, several research centers have been actively promoting the publication of research data, but even in the same field, data is not linked to each other, making it difficult to utilize. To solve this problem, we need a portal site for collaborative searches ”data catalogs”. In this poster presentation, we will report on the background to the implementation of ResourceSync, using the case of building a data catalog using WEKO3, which is being developed by the National Institute of Informatics, to organize the issues involved in linking with external repositories.