The list of entries of the Pralex lexical database (LDB) was at first built according to the Frequency Dictionary of Czech, later enriched by other entries from the Dictionary of the Standard Czech Language and continually enriched from the corpus SYN, too (so far optionally). To make the database an inventory of lexical units of contemporary Czech, as well as a base for a new middle-sized monolingual dictionary or other special dictionaries, we would like to expand it by choosing relevant lexical items from both newer reference resources (dictionaries) and material resources, e.g. other corpuses of written texts made by the Institute of the Czech National Corpus, various other databases (e.g. text archive Newton) or our own databases (excerption database of neologisms and special excerption database of various branches).