In the article it is overlooked the evolution of the notion “dialect” that combines the double essence: its belonging to both the locality and the language. During our studying of spreading of the dialects on the territory where the Latin language is basic we established that Romania had been separated on four large linguistic territorial parts. The last ones deeply changed the Latin language of those times under the pressure of different factors and geographical position. In the article it is also observed the role of the local dialects which are able to produce the language of the whole nation that is based on the historical, geographical, political and religious relations.