The article deals with the specific features of the German language on the Bavarian dialect lexical level. The dialect is remarkable for its innovations and variety of linguistic forms on all levels of its system. The notion “Bavarian dialect” and its correlation with literary German language is being researched. The comparative analysis reveals the facts of deviation from the standards of the literary German language, especially in vocabulary and semantics. The Bavarian dialect system is constantly changing, as any language system. We can analyze it from the point of view of two states: synchronic and diachronic. The first state is relatively more stable and functioning of the language units is rather regular. But this system condition is balanced only to some extent. At every step of its development, the system collects innovations at all levels of its structure: from phonological up to discursive. When their number starts to grow, the language system may change making all the new language units a new norm. A new step of its evolution begins. The aim of the article is to show the inner process of the language system self-development.