Yaghma Jandaghi is a great Iranian poet and writer of the thirteenth century. He was interested in pure Persian language. Jandaghi book title is Monshaat. His letters are there in the Monshaat. He did not write the letters of Arabic words. He tried to write all the letters with the word Persian. He made Persian compound words to make him use it in his letters. He was a great enthusiast. In this article we have investigated in his letters. Yaghma Jandaghi, Clean Language, Monshaat, Yaghma Jandaghi is a great Iranian poet and writer of the thirteenth century. He was interested in pure Persian language. Jandaghi book title is Monshaat. His letters are there in the Monshaat. He did not write the letters of Arabic words. He tried to write all the letters with the word Persian. He made Persian compound words to make him use it in his letters. He was a great enthusiast. In this article we have investigated in his letters. Yaghma Jandaghi, Clean Language, Monshaat,