The article dwells on some peculiarities of Tajik lexicon of “Muqaddimat-ul-adab” by Zamakhshari being one of the Arabic-Persian bilingual dictionaries, in which Tajik lexicon is occurred in a special meaning and freshness ones. It is noted that the majority of the Tajik words those ones included into the dictionary are still preserved in various dialects of modern Tajik language, and from this point of view, on the one hand, this indicates the author’s awareness of the live language of the people, and on the other hand, the value of the relevant dictionary is determined by issues related to histori­cal dialectology and formation of the live language of the people at the author’s time.