After the spread of Nimayi poetry, major changes took place in sonnet forms, and innovations were fostered in accordance with the age of modernity in language, expression, form, and content, so that little by little “ new sonnet” was formed. The poets of this movement made significant changes in these areas in sonnet. One of the modernist lyricists is Manouchehr Neyestani, who, considering the time of presenting his sonnet, should be regarded as one of the founders of modernization in the form of Persian sonnet. The purpose of this study is to explain the way he moved towards the modernization of Persian sonnet. The research findings show that he fostered significant innovations in the external form of the sonnet, including changes in typology, punctuation, number of verses, repetition of verses, meter, and rhyme. Nevertheless, his efforts to innovate in the content of sonnet have been analyzed too, and for this purpose, we have studied the narrative, imagery, and paradoxes in his sonnets. Most of these innovations first appeared Neyastani’ s sonnets and from there they found their way to the “ new sonnet. ”