In the BA thesis I devote to the Expressionistic era, which is trough Art Nouveau and Symbolism connected with old Slavic mythology and beliefs. I formally define and characterise Expressionism. I also summarise the general aspect of old Slavic mythology. Expressionism is then divided historically and with the help of an earlier historical era, Art Nouveau, I establish a connection and explain the usage of fabled and folk motives. With the concern of all elements I take Slovene aspect and historical current in art as the paramount link. Following the Slovene Expressionism coincidently leads to examination of three Slovene Expressionists. In short I present Symbolism and the meaning of symbol. In the part of BA thesis concerning Slavic mythology I summarise and present two representatives of Slavic gods and their fables, myths, superstition as well as their appearance. The final goal is to represent development of Expressionism trough old Slavic mythology and beliefs. In short I also take in account and present emotional aspect which is fundamental for expression in art.