The goal of the present paper is to explain the grounds of growing popularity of the German political party "Alliance 90/The Greens" in the second decade of XXI century and to evaluate the party's perspectives. Russian experts do not pay much attention to this political force while the works of the foreign political scientists cannot provide a sound explanation of sudden popularity surges of the party in recent years. General tendencies of the German party system development in the beginning of XXI century are con-sidered in the article as well as the main factors providing positive ratings of the Greens. The author comes to a conclusion that a fast popularity increase of the political force under consideration in 2011 and 2018 is not accidental but reflects some long-term tendencies. The interaction of five factors can provide an explanation of the Greens' success: upsurge of right populism, to which the Greens are the main opponents; deep crisis of German Social Democrats; value system changes in German society; the party's popularity among the young voters; internal development of the party that made the Greens more solid but open to the cooperation with other political forces. The research results help us make a forecast that the Greens' weight in German party system will grow in medium term. Nevertheless, they will not form a new 'people's party' because the very phenomenon of the 'people's party' in the modern world becomes outdated.