It has been known that science is an international professional field and it hasn’t national borders. In present study, the authors researched the migration flows of scholars in different countries, based on a study of more than a thousand scientists from several large countries that published in 2017 research papers on biology, chemistry, earth sciences and the environment. Everyone was asked about the current host country, country of origin, whether worked abroad and what factors caused the migration. It turned out that Switzerland has the largest share - 57% of the immigrant scientists (e.g. those who lived under 18 in another country), followed by Canada (47% of immigrant scientists) and Australia (45%). The lowest percentage of scientists - in India (0.8%), a little more - in Italy and Japan, but India - the largest exporter: 40% Indian scholars working outside the country. Among 40% of Swiss, 5% among Americans, but Japan has the smallest diaspora of scholars outside the country - only about 1%. The main reason for migration is the most commonly called payroll, professional conditions, etc. The study also showed that migration occurs most often between neighboring countries (cross-border migration), although cultural ties are also very important: e.g. the British constitute the majority of immigrant scientists in Australia, Moldovans in Romania, Italy, Spain and France. The study showed that 56% of UK scientists have foreign experience, while for Germany this proportion is 78% and for Americans - only "19%." The percentage of "repatriated" also varies greatly from one country to another. Spanish emigrants return home most often, and India, on the contrary, often leaves for good. Regardless of the country of residence or home, the main reasons for returning home are families or people.