The case category, which occupies an important place in the grammatical structure of the language and is manifested on the basis of its internal rules of each language, serves to create a connection between words in the language and to form a sentence. It is known that the case category in Turkic languages differs from each other mainly according to the number of cases and the variant in the suffixes. The article contains information about the case category in the kipchak Turkic language, as well as its grammatical indicators. When we examined the case category of the noun in "Codex kumanikus", a monument of Kipchak Turkic language, we noticed that there are certain differences compared to the modern Azerbaijani language. The similarities are mainly both morphological and functional. Different features of noun case categories in the modern Azerbaijani language are related to the large number of cases in "Codex kumanikus", the variant of suffixes, as well as the violation of vowel harmony, especially the harmony of lipped vowels.
“Codex cumanicus”, case category, noun, grammatical structure.