The book Javame Ahkam Alnojoom written by Abu Al-Hasan Ali Ibn Zayd Beihaqi is truly considered as a masterpiece on astronomy written in 6th century.  The prose of this book duplicates a good part of the Morsel prose in terms of lexical and stylistic features of the 6th century. This book has unique stylistic features including variety of iterations, various removals, specific application of phrases and words, writing features, specific application of pronouns and arrangement of components as examined in this paper. In this book, in addition to using old Persian words, difficult Arabic words have also been utilized, At times, even some rather low frequent words which are not included in dictionaries appear in this book