BACKGROUND AND PURPOSE: The text of the Shahnameh despite the common perception, is not a uniform text and if we accept the views of some Shahnameh scholars on the division of Shahnameh into two parts, mythological and historical, it can be said that in addition to the subject from a stylistic point of view, there are differences between these two parts. METHODOLOGY: In this research, which has done by analytical – descriptive method, nearly two hundred verses of the two mentioned parts were linguistically examined and compared. The verses have been selected in such a way that from the beginning to the end of Shahnameh, with the exception of Daghighi 's verses, after every thousands verses, four verses have been selected and examined. The obtained statistics are presented and analyzed in three branches of linguistic stylistic, namely phonetic, lexical and syntactic. FINDINGS: Relying on the study of verses that were selected from two parts of Shahnameh and analyzed, it can be said that this book, contrary to some theories based on its uniformity, does not have a unified structure and from a stylistic point of view, at different linguistic, intellectual and literary levels, there are significant differences in it. In other words, the separation of Shahnameh into two parts, mythical and historical, is not only discussed by the themes, rather, Ferdowsi's different language and style of expression in each of these two sections is the basis for separation. CONCLUSION: The research results confirm the aforementioned assumption. Phonetically, the differences indicates the variety and musical and phonetic strength of the first part compared to the second part. Literally, the first part has an older color than the second part by having ancient words and names and using more prefix verbs. At the syntactic level, the precedence of verbs and additional group is effective in blowing the epic spirit to the first part and distinguishes it from the second part.