Problem setting. Since the European Commission has emphasized openness in science and innovation, it has been natural for relevant mandatory requirements to appear in EU research grant programs, including Horizon Europe, the main one. In principle, the very need to meet these requirements is a sufficient motivation for the introduction of open science in Ukraine and the development of the relevant National Plan, an important European integration tool. analysis of recent researches and publications. Domestic scholars who have studied this issue include: Drach I.I., Vasylenko A.Y., Bruy O. and others. Foreign researchers are: Lichten C.A., Hafner M., Wooding S., Cooper S.F., KhatibA., Treuille J., Barbero J. Lee, Beenen M., Leaver-Fay A., Baker D., Popović Z., Eiben C.B., Siegel J.B., Bale J.B., Cooper S., Khatib F., Shen B.W., Brownstein J.S., Freifeld C.C., Madoff L.C., and others. Purpose of the research is to analyze the essence of open science, its goals, advantages and disadvantages, as well as the demand for and prospects of large-scale implementation of open science policy. article’s main body. For the international community, the role of open science has become even more apparent during the global crisis caused by the coronavirus pandemic, which has shown humanity the key role of open access to scientific information, rapid knowledge sharing, and collaboration between scientists in overcoming global challenges. Today, it is no exaggeration to say that the effective and rapid implementation of open science in Ukraine can become the basis for restarting the national scientific system, which is not fully competitive in the global dimension and suffers from the vestiges of the past. In particular, this concerns the development of a renewed national scientific culture based on academic integrity, cooperation, and a focus on the needs of society. The emergence of a national plan for open science in Ukraine is the beginning of systematic work at the state level, which is to be welcomed. Obviously, we need to act quickly, because every day the gap with the EU countries will increase and may become critical, complicating European integration processes. The bad news is that the implementation of open science always means additional efforts and/or costs (for new research infrastructure, payment for open access publications, awareness raising and training, etc.) that Ukraine may not be able to afford, especially given that a huge share of the national budget will be spent on defense in the coming years (almost 50% in 2023). It is also worth remembering the need to focus on young scientists, who will need additional support but can become effective agents of change, as open science will provide them with many tangible benefits, and the ideal time to develop the relevant skills is at the beginning of their scientific career. conclusions and prospects for the development. Given the benefits of open science, compliance by Ukrainian scientists with certain requirements will facilitate their integration into the global scientific community. Since open science is still in the early stages of its evolution, consolidated information on trends and practices will help to show where policy development can be useful and where participants in open science initiatives have already been able to create their own useful practices. However, open science can also have a negative impact on the research system, and this should also be highlighted and investigated. It is advisable to review the systems for evaluating research and professional performance in order to bring them in line with the principles of open science.