Texts are related to each other, the earlier texts influence the later texts. One of the myths that has had a significant impact on Iranian culture is the myth of the vegetation deities. The story of Siavash in Shahnameh is a great example of it. This research has examined the young adult novel "Vash Vash, Vashi, Vashan, Siavash" with regard to the myth of the vegetation deities and the story of Siavash. In the meantime, the question is how to systematically examine the relationship of these texts and, considering the common nature of these three narratives, find a theory that can be used to examine the mythological aspect of the work and obtain a classification of it. In response, the relationship of these texts with each other with three types of intertextuality, i.e. intertextuality, hypertextuality and paratextuality, and according to the eighteen common motifs of the narratives of vegetation deities, have been investigated; In the following, according to the intertextual and hypertextual analysis of the works, the novel has been analyzed from the perspective of archetypal and mythic criticism and the literary genre appropriate to each myth. Based on the obtained results, out of the eighteen common motifs, the story of Siavash have taken fifteen motifs and the novel have taken ten motifs; Also, all four myths are present in this novel.