ENThe identity of the Polish minority in Lithuania isn't a new problem for researchers in Poland, Lithuania, and even the US. One of the most interesting periods in the history of Poland and Lithuania connected with the Lithuanian National Movement and the collapse of the Russian Empire at the beginning of the XX century. It was a time when the old nation of the Polish-Lithuanian Commonwealth moved down and finished its existence. Also, new modern Polish, Lithuanian, Latvian, Belarusian, and Jewish nations started to be born and developed. This period brought a lot of changes, not only in political life. Also, big economic and cultural changes took place. Aristocracy and land owners slowly lose their roles as main initiators and coordinators of economic-social life. New modern intelligence grew up, Polish intellectuals in Lithuania usually came from aristocracy and Lithuanian leaders - usually from circles of the peasantry or the Catholic Church (priests). Conflicts between these two groups started very quickly. Nevertheless, the Lithuanian National Movement was really strong and had positive results, as the Republic of Lithuania was created and recognized by the world community. Poles of Lithuania were split between two states, between two Homelands. There was also a utopie theory that the Poles of Lithuania were a separate national group from the Walloons in Belgium. It could be the topic for separate research. Key words: Polish identity; Lithuanian National Movement; Polish-Lithuanian Commonwealth; collapse of Russian Impere; national states.