A present-day scientific experiment requires organized and self-organizing interaction of hundreds and thousands of specialists. We can offer some recommendations for improvement of the legal mechanisms of international scientific and technical cooperation. The creation of a unified national infrastructure supporting international scientific and technical cooperation of Russian organizations and research teams should be singled out as a separate project within the framework of a federal target program. It seems necessary to develop a special contract system for organizations participating in the Megascience projects, as well as a procedure for selection, monitoring and reporting standards. The issues of recruitment and training of the personnel involved in the functioning of the infrastructure of the Megascience projects are of particular relevance: competency profiles of experts in the management of international research projects should be developed, and the issues of their educating should be resolved as well. An important mechanism of interaction between national, international and foreign entities within the framework of the implementation of the Megascience projects is the creation of a single specialized web portal that would combine the resources of all the participants, simplify and accelerate interaction between research teams, and provide users with the necessary methodological support, in the national language as well. The improvement of legal mechanisms for attracting international and foreign entities for the implementation of the Megascience projects should be based on the creation of an infrastructure that provides administrative, financial, organizational, and legal support for research teams. At the same time, this activity should take into account the opinion of scientists themselves and never directly interfere in scientific and technological processes, allowing for a flexible approach to solving various issues.