Political parties are one of the two basic means to secure a democratic rule. They allow formation of opinion of the citizens and its aggregation and manifestation via elections. In their functioning or dysfunctions, the quality of the complete political system is being proved. For this reason, political parties become the field of the study of political science. Based on the classical typology of G. Sartori and J. Blondel the authors describe systems of political parties in the extended European Union and other Western European states. They analyse their current state, the important parties involved, conflict lines, development, changes, and policies in particular countries.