Translation is a complicated subject,in which there are manifold problems since its establishment.The question of translatability and untranslatability is a heated topic in translation theory.Different experts have different ways of demonstrating translatability and untranslatability.Since the deconstructive thinking was taken into the field of translation,there have been more and more discussions about Derrida and his views on translation.The author,starting from the point of different understandings of Roman Jakobson's three types of translation,explains Derrida's ideas about translation from two aspects,translatability and untranslatability.Finally,the author gives some implications during the process of translation.