This article is dedicated to the 75th anniversary of academician Gheorghe Rusnac. The authors examine four main steps in the scientific, didactic and managerial activity of the researcher, professor and manager Gh. Rusnac. The first stage - the years 60-80, which we associate with the studies of Gh.Rusnac at the State University of Moldova, the Faculty of History (1965-1969), then the doctoral research at the Department of History of the respective university (1971-1974), and post-doctoral studies in history at the State Pedagogical University of Moscow (1984-1986). The second stage - the 90s, with quantitative and qualitative new reflections in the formation and evolution of national political science, first related to the emergence of the new state - Republic of Moldova in 1991. The third stage - the end of the 90's until the end of 2007, a qualitatively new period in the scientific field of the scientist and the rector of the State University of Moldova Gh.Rusnac, highly appreciated by the Academy of Sciences of Moldova. On 17 May 2000 for outstanding merits in the development of political science Mr. Gh.Rusnac is elected as a corresponding member of the Academy, and more than seven years, on April 3, 2007, he is already a member of the same Academy.  The fourth stage - the end of 2007 until now, which we share in two periods: a) the activity of Mr. Gh. Rusnac as Ambassador Extraordinary and Plenipotentiary of the Republic of Moldova In the Republic of Italy and Republic of Malta (26.11.2007-22.12.2011) b) Vice-president of the Academy of Sciences of Moldova and senior scientific collaborator, Laboratory of Political Sociology, State University of Moldova.