International students have been noted as the driving force behind the development of the economy and higher education institutions of the sending country. After graduation, it is assumed that graduates who work in their home countries give a positive effect to the alma mater through joint researches. In fact, international student support has been actively carried out in several universities. On the other hand, there is a finding that foreign students who returned to their original countries, left low performance. Therefore, the effect of international fame improvement through international students has not been demonstrated. Previous studies to measure the joint research after returning to original countries does not exist. First of all, I designed a system for extracting laboratory with many international joint research from a database in the university. Subsequently it is scheduled to analyze whether research networks are maintained by graduates of the laboratory after returning. I designed the system for extracting international joint research from university researchers information database. In the current scheme, it is not able to extract the student who graduated without co-authored papers with faculty. It is the task of the future.