The article contains review of synthetic and analytic structure Indo-European languages. Most of all attention is given on examination of analytic cases of grammatical meaning expressions in modern Russian and Lithuanian language, which mainly is synthetic by its structure. Development of analytic elements in synthetic languages is internal centuries-old process and has different rate of growth within various languages Modern Russian as language of synthetic structure with analytic elements and modern Lithuanian as language of pure synthetic structure. However, tendency to analytic expressions is liven up by external, social processes too. According to the modern Russian and Lithuanian main of such processes are democratization, Europeanization, globalization.