The present thesis deals with the variation of prepositions na and v(e) in the contemporary Czech. On the basis of the previous literature it follows the distribution of these prepositions and their morpho-syntactical relations. The attention is focused on the description of linguistic collocations based on corpus-analysis of several nouns. Furthemore, the hypothesis for using the prepositions are outlined. The results of the analysis are used for the last part of the thesis - the sociolinguistic research. The aim of this thesis is to describe the distribution of the prepositions and point out some differences on some representative examples.